原文未缩减 gitarrelieber – a CDer since 2003
节选自The Economist (@ 18 June 2004)
If so, then depending on your local laws you may have been participating in what economists call the "informal" or "grey" economy. In essence, the grey economy consists of legal activities whose participants fail to pay tax or comply with regulations. The informal (or "underground" or "parallel" economy) is often taken to mean something broader, including illegal activities such as prostitution and drug dealing as well, although there is no agreed strict definition.
The grey economy is often thought of as something found at the margins of poor countries, such as a hawker stand in Thailand or a roadside vendor in Ghana. But that is misleading. Although it represents a greater share of total output in poor countries, it exists in rich and poor places alike. Recent research suggests that the grey economy is growing. Moreover, a new study suggests that it may be slowing the overall economic growth of developing countries.
By its very nature, the informal economy's size in any country is hard to observe. In a paper published a couple of years ago ("Size and Measurement of the Informal Economy in 110Countries Around the World," World Bank Working Paper, July 2002), Friedrich Schneider, of the Johannes Kepler University of Linz, exhaustively examined the ways of estimating it. There are two basic approaches. The first is direct: you could ask people whether they dodge taxes, or look at the results of spot tax-audits. However, people are unlikely to confess to breaking the law, and tax inspectors do not usually check on a random sample of the population. So the second method, indirect detective-work, is better. For example, you might compare data on cash transactions or electricity consumption with official output figures. If the use of cash or electricity is growing much faster than the measured economy, this might indicate that the informal share of total activity is rising.
Using such techniques, Mr. Schneider estimated that the informal economy in developing countries in 2000 was equivalent to 41% of their official GDP. In Zimbabwe, the figure was 60%. In Brazil and Turkey, around half of non-farm workers are in the informal sector. In OECD countries the share of the informal economy was lower, but far from negligible, at 18%.
There is little mystery about why the informal economy exists. There are a lot of advantages to operating in the shadows. For a start, there are no income taxes to pay. Avoiding social-security charges, which often drive a chunky wedge between take-home pay and employers' wage bills, can both cut labour costs and thicken wage packets. People can also save a fair bit by ignoring safety, environmental and health rules, not to mention intellectual property rights.
Indeed, in cross-country comparisons, the more expensive and more complicated are taxes and regulations, the bigger is the informal economy as a share of GDP. That explains why, among rich countries, Spain, Greece, Italy and Belgium have some of the largest grey economies and why America, Canada and Switzerland have much smaller ones. In recent years, the growth in the grey market in some poor countries may owe a lot to the International Monetary Fund's austerity programs, which increase taxes and thus encourage many entrepreneurs to opt out.
A booming grey economy sounds like good news, if only because many of the officially jobless are in fact earning a living. So if the poorest are winning, who loses? The entire economy does, according to a new study by Diana Farrell of the McKinsey Global Institute. The price for having a large grey economy can be much lower productivity. Grey firms tend to be small and want to stay that way lest they come to the attention of the authorities. However, their small scale limits their ability to make the most of new technology and business practices.作者: 胡子长了 时间: 2010-8-18 10:08
1.1.4. 公司规模与创新能力
V1 综合版本 感谢 sunflower82, 200702061, Scarlettma & daisy88117
大公司和小公司的R&D (Research & Development 鉴于不少同志不知道这个全称)：
第一段说技术转化为生产力，然后商业化，往往是从investment在R&D上开始的。一般来说大公司在R&D上的investment会很多。按道理来讲，大公司应该在innovation方面有很多，而且收获更多。事实上，最近的一个研究发现，反而是小公司比较好，获利更多。
第二段解释为什么小公司比较好：一个公司要长期保持技术上的秘密很难(Golden课外补充：除非Resource-based Theory研究得很好，开发出不少Impediments to Imitation或者First-mover Advantages。)，因为/而且小公司很擅长从大公司那边得到现有的技术。
1 有一个题目是下面哪一个选项支持了第二段的说法。我选了一个A说是大公司的R&D人员会跳槽去小公司。
2 gyz12 740 从第二段描述小公司的情况里面可以infer出什么 我选了小公司员工来自于大公司
3作者会同意以下哪个statement，选项有个Very few information/knowledge is transferred from small enterprises to large enterprises.
4 feifeizoe 750 V39 第二段的中small firm有什么优势：促进创新。作者: 胡子长了 时间: 2010-8-18 10:08
文言文 nowwsy 确认，但注意(楼主为V1.1，古文为V1.2，但作用/in order to相同)
V1 jiayini85
讲了社会中，ART 表演的生产销率问题。
第一段说别的东东生产效率都上去了，但是art表演没有，cost一直超过正常的inflation，然后讲了art 的cost为什么降不下来的原因，其间举了个例子（而且出了个in order to 题），(V1.2)说一部45分钟的表演，他的productivity从来没有下来过：因为一部45分钟的表演，就必须演满45分钟，不可能像manufacturing那样通过缩短工时来提高效率（不过这道题我不确定，待后面的朋友去验证吧，如果发现我有误的话，立刻拍砖啊，不要误导更多人）。这是第一段
第二段用了两个人的study来讨论，第一个反驳了第一段的观点，怎么反驳的我忘了，好像没有出题点。第二个人的研究是资料数据统计，说N个剧院里的情况的确像第一段里面说的那样，cost一直上升。但是最后第二个人对第一段的解释的支持是带让步的，好像最后来了句什么话，总之不是完完全全赞同第一段的内容，文章的套路也很典型，突出“qualified opinion”的感觉
此段举了个例子关于某个Orchestral (有题)
V2 2009-11 XOXO简易版阅读
第一段：关于一个模型叫做cost disease，就是认为古典音乐艺术之类的成本没有随着经济发展大幅增加，因为科技发展可以使得其他生产规模化降低成本，但是每个观众的成本却没有增加一个什么人认为资金在音乐艺术方面投入不够多，然后他的观点立即被否定，否定他主要有两个原因。定位第一段：sponsor and subsidy，可以提供更多的funding，使得available to 更多的人
第二段：批判，科技发展也使得古典音乐能在更大的礼堂公开演出使得更多的观众得以享受；好像是说资金投入在功放（amplification）上了，如果没有amplification，那么表演者只能表演给更少的人听（这里有考题）。recording和broadcast也是得益于科技发展。
第三段：其实因为agency和经理使得一些star出场费非常非常高，也使得整个音乐艺术成本增加，使得这一项商业成为一种什么和什么的混合体，大意好像是市场竞争和个人什么……
考点集中在一,二段
1 逻辑类比，哪项更像cost disease 描述的：据说四个错误选项很明显
2 下列哪项是对的，stars 要的钱越来越多了/agent要的钱越来越多了：stars。因为我觉得agent 是帮助star 得到钱，本身拿不到钱。
3 音乐的费用会降下来，如果下列哪项假设成立：说free market的。确定。最后一段明确说了现在不是free market。
4 a和b的观点在那个方面相同
5 还有一题是那个45分钟演奏的例子in order to/有一个例子作用题：Provide an example related to one aspect of labor costs of
6 这一段第一个学者也举了个例子：说明了productivity并没有上升到足以抵消inflation影响的程度。
7 Why amplification：如果没有amplification，那么表演者只能表演给更少的人听。
8 sponsor and subsidy的作用：可以提供更多的funding，使得available to 更多的人作者: 胡子长了 时间: 2010-8-18 10:27
文言文 vitalia (Golden自行确认)
V1
P1:先让步,一般认为:satisfactory(员工满意度)还有一个什么因素是员工离职与否的决定因素.然后,转折说embedment是另一个决定因素,然后就列举了embedment的三个因素
P2:转折,但是embedment不仅能够促进员工留住,而且也有可能促进员工离职.然后是列举了两种情况: 1)connection使得员工有更多机会去了解新的工作机会,从而离职; 2)embedment可能会使得员工在公司和家庭之间产生矛盾.
1 主题题 注意作者TS的语气，有无强转折，强对比等
2 in order to 题
3 except细节(参考：有可能是背景里的第三四两段的小列举/第5段首句)：Employee considers company as a community’s big part
Background：(据说提供者叫)巴神
According to Mitchell et al. (2001), job embeddedness represents a broad cluster of ideas that influence an employee's choice to remain in a job, operating like a net or a web in which an individual becomes enmeshed. A person who is highly embedded has many connections within a perceptual life space (Lewin, 1951). Moreover, a person can become enmeshed or embedded in a variety of ways (both on and off the job). The critical aspects of job embeddedness are the extent to which the job is similar to or fits with the other aspects in their life space, the extent to which the person has links to other people or activities, and the ease with which links can be broken--what they would give up if they left. These dimensions are called fit, links and sacrifice. Less concerned with the influence of any one specific connection, job embeddedness focuses on the overall level of connectedness (Mitchell et al., 2001).
介绍工作嵌入度的三个方面：fit （适合）, links（联系） and sacrifice（损失）
According to the theory of job embeddedness (Mitchell, Holtom and Lee, 2001), an employee's personal values, career goals and plans for the future must fit with the larger corporate culture and the demands of his or her immediate job (e.g., job knowledge, skills and abilities). In addition, a person will consider how well he or she fits the community and surrounding environment. Job embeddedness assumes that the better the fit, the higher the likelihood that an employee will feel professionally and personally tied to the organization.
讲第一方面----fit（适合），员工的个人价值，职业目标和未来计划必须与公司文化以及他/她个人的工作相一致，也就是fit。员工自己也会考虑自己是否fit其所属团体与环境。越fit，员工越有归属感，越不会跳槽。
Job embeddedness theory suggests that a number of threads link an employee and his or her family in a social, psychological, and financial web that includes work and non-work friends, groups, the community, and the physical environment where they are located. The greater the number of links between the person and the web, the more likely an employee will stay in a job (Mitchell et al., 2001).
讲第二方面----Link（联系）。与方方面面联系越紧密，员工越愿意留在公司。注意这段的小列举
The concept of sacrifice represents the perceived cost of material or psychological benefits that are forfeited by organizational departure. For example, leaving an organization may induce personal losses (e.g., losing contact with friends, personally relevant projects, or perks). The more an employee will have to give up when leaving, the more difficult it will be to sever employment with the organization (Shaw et al., 1998). Examples include non-portable benefits, like stock options or defined benefit pensions, as well as potential sacrifices incurred through leaving an organization like job stability and opportunities for advancement (Shaw et al., 1998). Similarly, leaving a community where they are highly involved in local organizations can be difficult for employees.
讲第三方面----sacrifice（损失）。员工在各方面损失越大，越不愿跳槽。注意这段的小列举作者: 胡子长了 时间: 2010-8-18 10:28
1.1.16. ★公司选址 (GWD原题)
V1 satsumakiwi
Q24~Q25: GWD32-Q13-Q14
Manufacturing site location is an important consideration in determining the optimal deployment of a firm’s production resources, but one that is usually given only limited attention. Decisions about location are often based purely on quantitative analyses (reference: syle) that trade off transportation costs, economies of scale, and other cost-based variables. This practice, however, can lead to suboptimal results, as decision-makers tend to focus only on easily quantifiable factors. A further disadvantage of strictly cost-based methods is that they tend to focus on cost advantage factors, which are often transitory Government regulations, tax systems, and exchange rates can quickly change. Strategies based on such parameters may eventually be rendered obsolete by the very factors that first created an advantage.
In contrast, qualitative issues (reference: syle), which are frequently neglected in choosing manufacturing site locations, are often central to creating and supporting a competitive advantage. For example, the level of skill possessed by the local workforce varies with location; consequently, location can affect the ability of firms to implement skill-based process technologies. When formulating a site location strategy, companies should therefore emphasize qualitative factors to ensure that the chosen strategy supports the company’s overall business strategy. Only after establishing a set of desirable location options should companies refine choices using cost-based factors.
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Q13. The passage suggests which of the following concerning qualitative methods used in choosing manufacturing sites?
A. They are more likely than are quantitative methods to identify issues crucial to maintaining a competitive advantage
B. They are least useful to companies with relatively low levels of manufacturing technology
C. They have little value when applied to decisions other than choice of site
D. They are more risky for decision makers than are quantitative methods
E. They are used more frequently by multinational corporations than by companies with strictly domestic operations.
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Q14. According to the passage, analysis of quantitative factors is best used for which of the following?
A. Determining strategies for offsetting qualitative disadvantages in manufacturing site locations
B. Evaluating manufacturing site-location parameters affecting long-term competitive advantage
C. Choosing manufacturing site locations that have access to optimal workforce populations
D. Narrowing manufacturing site-location options arrived it through qualitative analysis
E. Making decisions about business considerations other than location of manufacturing sites
另外羅己有一題GWD變形:
30. GWD21-Q30:
In the past, most children who went sledding in the winter snow in Verland used wooden sleds with runners and steering bars. Ten years ago, smooth plastic sleds became popular; they go faster than wooden sleds but are harder to steer and slow. The concern that plastic sleds are more dangerous is clearly borne out by the fact that the number of children injured while sledding was much higher last winter than it was ten years ago.
Which of the following, if true in Verland, most seriously undermines the force of the evidence cited?
A. A few children still use traditional wooden sleds.
B. Very few children wear any kind of protective gear, such as helmets, while sledding.
C. Plastic sleds can be used in a much wider variety of snow conditions than wooden sleds can.
D. Most sledding injuries occur when a sled collides with a tree, a rock, or, another sled.
E. Because the traditional wooden sled can carry more than one rider, an accident involving a wooden sled can result in several children being injured.
考題把(C)選項改寫，我記得答案變成Plastic sleds比較便宜，許多人願意購買使用。作者: 胡子长了 时间: 2010-8-18 10:31
1.1.17. 品牌认知度**
V1 aprilarchy 710
关于brand recognition
第一段说一项调查 half of surveyed people said they were loyal to a brand are no longer more this year. (有考题)
第二段肯定这个调查的结果，说现在人们获得information的渠道越来越多，报纸，杂志都有很多对于product 的专业评论，people are more likely to experiment the product, 因为多渠道的信息让他们可以take chances of far less (maggie520 updated) risking
第三段是说这种现象对很多行业都有影响，举例到贴牌加工的，所以消费者不会愿意pay high price for 本质上一样的商品（有个一infer的题）
1 take chances 的infer题：人们purchase unfamiliar product(购买不了解的产品)的风险，或者类似选项
2 marketing 策略
3 innovation是不是还管用作者: 胡子长了 时间: 2010-8-18 10:34
1.2.1. 美国妇女家庭地位和财产税的关系**
感谢 wtbzeus
文言文 Golden & penglili 已确认
V1
Chinese & English 整合版
关于十九世纪美国妇女的财产权的长文，大概有两片短文的长度。讲状况及一些学者的评论。
第一段：概括某一新法案M实施前的状况，在common law的情况下，妇女结婚后财产就归丈夫所有了。此时丈夫对妻子的财产有很大的支配权利。妇女只有通过一个似乎叫equity court的机构才有可能得到对自己财产的权利。
第二段：讲十九世纪中期爆发了经济危机。因为有人担心“丈夫破产会连带将妻子的财产也失去”，于是出来了一个新的法案。学者1(S)的观点是这个法案极大的改变了妇女的status and 对自己结婚前后的财产的权利。
第三段：讲了不同学者(1. Sammas, 2. Beard, 3. Salmons)间的评价。第一句话是学者2(B)的观点，是他认为在M实施前已经有equity court这个东西，对于“保护妇女财产”有积极的作用了。然后是学者1继续反对(或者学者3站出来)B的观点。 说以前的equity court在不同的州开展的情况不一样，例如Connecticut 和 Massachusetts州，在这些州里面有很多传统保守实力，反对这种社会、法律发展的趋势，阻碍了M的实施。最后一句话，讲了有些人愿意接受这种法律，也是为了破产的丈夫把财产转移给妻子，赖债权人的钱。
In English
Married women's property rights and their social status
Saying in the 18 and early 19 century, common laws dictated that when a woman is married, her husband takes over all her properties. The man had control the right to use the woman's properties while she lived and became the owner of the properties upon the woman's death. Only one thing can prevent this from happening, something like "pre-marriage settlement"
Then. some law about women's right of property was finally established!! then blah blah blah, how good the law was and things like that. Then, a scholar named Sammas? said this law substantially changed women's status.
BUT, another scholar named Beard? disagreed with Sammas and said the effects of this new law was overstated because before this new law was established, there always existed "equity court" that serve the same purpose.
BUT, a third scholar named Salmon came out to challenge Beard. Salmon said equity court can't do much because most states were very hostile against equity court and in the cases where the court gave women the right of properties, some were attempts made by men to transfer all properties to their women to avoid consequences of bankruptcy.
1 主旨题：(提出观点) 讲述社会变化，对比学者观点/to chronicle laws regarding women's right of properties and examine the implication to women's status (文章的重心是在第二个学者的言论，应该属于提出观点的文章，要突出这个)
2 (实施M后来的结果？)答案：M的实施并不普遍，并且对它的接受不大好。
3 立法原因：有一题是关于婚后财产是归老公支配的。
4 这些州立法的时间：(大家考试的时候注意下)
5 通过法律你能infer出什么：not universal in all states (Universal同义替换，康涅狄格和麻省为证)
6 最后一句的作用：(猜测)作为Salmons反对Beard的又一个例子。
7 inferred from the passage, what would Beard mostly likely think of equity court: it substantially improve women's status作者: 胡子长了 时间: 2010-8-18 10:38
文言文 vitalia & xAriAx 基本确认
V1 (V37)
第一段：爱尔兰的女权运动由1920s开始，因为那时候爱尔兰争取民族独立，逃开大不列颠的统治。其中妇女运动suffrage(这个词意为政治性选举的)选举权, 投票权。但是，研究人员发现，compare to modern Irish女权运动，尽管爱尔兰妇女运动表面上卓有成效，事实上并没有改变女性在爱尔兰的政治地位及其他（就是说没有实质作用，只是表面光鲜）。
第二段：为什么会有这个discrepancy呢？因为研究人员没有考虑到这三个aspects，blahblah（好像有细节题）。所以能结论是不能拿1920年的女权运动跟现代的比。。。最后一句话有考题。
核心内容：
I 评价了一个传统研究方法的缺点
II 爱尔兰女性找wage labors有限制
III 新政不是造成限制女权的真正原因
IV过于集中研究主权运动会对爱尔兰妇女的研究有distortion
V 如果能证明主权运动的主体是广大爱尔兰妇女，则能削弱文章论调（文章说不能确定）。作者: 胡子长了 时间: 2010-8-18 10:40
1 主题：学者们利用了别国的研究方法导致结论上有偏差；Evaluate / point out potential shortcomings of a traditional historical research approach
2 第二题highlight新政府的政策（原文是political factors）了，问作者同意哪个观点？选的是其实这些不是造成限制女权的真正原因
3 跟女性的economic status有关的问题：女性找wage labors有限制。针对列出那些原因的一句话，返回原文应该容易找到答案
4 说明她们的很多经验是来自她们的前辈，那些feminism活动的组织者的（这里有一道题目）
5 作者态度题：negative
6 过于focus在主权运动，会导致什么：对爱尔兰妇女的XX研究有distortion
7 如何削弱旧观点“就是他们没有不能代表妇女的解放”：可以说是发现了一个文献什么的，里面记载了，这些运动的主体是广大的妇女劳动人民(they dunno how many women actually participated and stuff like that)(由于现有的对爱尔兰妇女主权运动的account并不是很全，所以不容易得到XX的结论)。作者: 胡子长了 时间: 2010-8-18 10:49
文言文 vitalia 基本确认
V1
Indian art on the cliff
P1 a kind of carving on the cliff in northwestern US regions where a Indian group lived is called vertical something.
P2. because a female researcher found this kind of art in lakota people's territory and the territory of other oyata culture (oyata includes lakota), she attributed the kind of art exclusively to oyata people. she also found this kind of art to be a communication system.
P3. the author thinks the existing archaeological evidences are not strong enough to support the female researcher's conclusion that the kind of art on the cliff only belongs to oyata culture. the author thinks this kind of art belongs to many culture of a certain time. his evidence is that in some place in Canada, there is also this kind of art.作者: 胡子长了 时间: 2010-8-18 10:58
文言文 nowwsy 已确认
讲的是人类眼睛的眨眼之类的一种定义为M的行为可以使人们看清楚静态物体stationary objects
第一段：开头就提到一个假设。第一段先给了一个定义，解释了Microsaccade这个东西。大概是说什么眨眼之类的眼睛自己的运动，然后说researchers have been unsure about the function of Microsaccade，甚至曾经有的researcher have gone so far居然说这种眼睛自己的活动可能会因为blurring什么的对眼睛造成伤害。（后注：这种假设是错误的）。（这里有题，问文章提到这种对于Microsaccade功能的解释是为什么）接着第一段后面说了又有另外一种解释，说是这个M吧，可以让人们的眼睛看清楚静止的物体。
第二段：前半部分说了支持这种假设的证据，后半部分提出反对的意见，讲了一些眼球看物体的反应。还是拿青蛙作对比，说青蛙看不见静止的只看见活动的，但是人可以，因为人的眼睛有motion还是怎么的。说这种睡眠比较为深度睡眠更难醒，而且单从predator的角度来看，这种假设也难合理
第三段：继续提一些反对这种假设的证据。说了一个实验，就说科学家找来一群人，让他们一直对着电脑频幕的一个central dot看，然后问他们对于电脑屏幕上的peripheral dot的视觉反应。接下来这段...我不是很明白他们之间的因果关系...反正大概意思是说，那些人看着看着，觉得那些peripheral dot在慢慢消失fading，而他们的Microsaccade也在逐渐变缓(sparser数量减少and slower)，然后又恢复normal when the peripheral reappear。
结构：提出假设+推翻假设+实验结论
补充：首先提出一个概念Microsaccede，下简称m，中文是微动眼，指眼睛自然的细微运动。研究人员提出假设微动眼的作用可以使我们看得清静止的东西。在进化的过程中，视觉在看动态事物方面进化较快，之后讲了一些原因，有一个是因为动物可以见到猎物逃走。人的眼进化出微动眼帮助人不仅看到motion还能够看到静止事物。之后对比了人和青蛙。最后视觉神经是如何发生作用。神经一般是在看motion时才firing，而微动眼帮助人类即使在看静止的事物神经都可以keep firing。作者: 胡子长了 时间: 2010-8-18 11:06
考题：
1）What is the theme of the passage：选主要讨论一种假设
2）What is the function of the substance of Microsaccade：illustrate科学家对于Microsaccade功能不能达成共识。
3）视觉方面的神经元的运作方式之类的。比如什么neuron会 generate more electro...（有着“电”的词根的某单词）with response to moving objects than to stationary objects（有题）
4）infer题：从文中可以推出最后一段试验中的subject干什么呢：是M帮助人看到什么东西来的。
（这题要对experiment的结果要求看仔细点，关系有点复杂。）记得其中2个选项是M开头，3个选项是visual neutron开头。
5）第二段有一个in additional，问作用
6） 推断视觉神经在青蛙的作用：备选对motion的反应比对静止事物强烈得多
7）主题
8）一道题是下面哪一条会削弱：是关于fixational eye movements和动物对所处环境危险程度的敏感程度的……
And yet only recently have researchers come to appreciate the profound importance of such “fixational” eye movements. For five decades, a debate has raged about whether the largest of these involuntary movements, the so-called microsaccades, serve any purpose at all. Some scientists have opined that microsaccades might even impair eyesight by blurring it. But recent work has made the strongest case yet that the seminuscule ocular meanderings separate vision from blindness when a person looks out at a stationary world.
Indeed, animal nervous systems have evolved to detect changes in the environment, because spotting differences promotes survival. Motion in the visual field may indicate that a predator is approaching or that prey is escaping. Such changes prompt visual neurons to respond with electrochemical impulses. Unchanging objects do not generally pose a threat, so animal brains – and visual systems – did not evolve to notice them. Frogs are an extreme case. A fly sitting still on the wall is invisible to a frog, as are all static objects. But once the fly is aloft, the frog will immediately detect it and capture it with its tongue.
Frogs cannot see unmoving objects because, as Helmholtz hypothesized, an unchanging stimulus leads to neural adaptation, in which visual neurons adjust their output such that they gradually stop responding. Neural adaptation saves energy but also limits sensory perception. Human visual system does much better than a frog’s at detecting unmoving objects, because human eyes create their own motion. Fixational eye movements shift the entire visual scene across the retina, prodding visual neurons into action and counteracting neural adaptation. They thus prevent stationary objects from fading away.
The results of these experiments, published in 2000 and 2002, showed that microsaccades increased the rate of neural impulses generated by both LGN and visual cortex neurons by ushering stationary stimuli, such as the bar of light, in and out of a neuron’s receptive field, the region of visual space that activates it. This finding bolstered the case that microsaccades have an important role in preventing visual fading and maintaining a visible image. And assuming such a role for microsaccades, our neuronal studies of microsaccades also began to crack the visual system’s code for visibility. In our monkey studies we found that microsaccades were more closely associated with rapid bursts of spikes than single spikes from brain neurons, suggesting that bursts of spikes are a signal in the brain that something is visible.
In our experiments, we asked volunteers to perform a version of Troxler’s fading task. Our subjects were to fixate on a small spot while pressing or releasing a button to indicate whether they could see a static peripheral target. The target would vanish and then reappear as each subject naturally fixated more – and then less – at specific times during the course of the experiment. During the task, we measured each person’s fixational eye movements with a high-precision video system.
As we had predicted, the subjects’ microsaccades became sparser, smaller and slower just before the target vanished, indicating that a lack of microsaccades– leads to adaptation and fading. Also consistent with our hypothesis, microsaccades became more numerous, larger and faster right before the peripheral target reappeared. These results, published in 2006, demonstrated for the first time that microsaccades engender visibility when subjects try to fix their gaze on an image and that bigger and faster microsaccades work best for this purpose. And because the eyes are fixating – resting between the larger, voluntary saccades – in the vast majority of the time, microsaccades are critical for most visual perception.作者: 胡子长了 时间: 2010-8-18 11:09
2.1.2. 鸟预测地震**
V1 tracy沁
鸟可以预先感知地震
P1 开头是说二月的什么（好像是天气）一般稳定，但是就在具体的某年某月某日，不寻常发生了。一群seabirds 飞到了interior of……。后来这里发生了地震。之后还说有类似例子。
P2 解释这一现象
P3 忘了
第一题 问文章举了哪种动物的例子 选E - birds，选项有A - wildlife 其他的忘了
主旨题A - a argument of ……over a phenomena; E - a research report about a phenomena (题目是不是report忘了，反正有research) 其他选项都不对，应该就这两个里选，我选了E rainrooney 720 V38 说应该选A，因为作者只是提供了这么一种可能性，并没有深入的科学研究。作者: 胡子长了 时间: 2010-8-18 11:09
V2
P1 use acoustical method in a noisy environment.
P2 talk about why they can avoid the noise. Basically only focus on how the acoustics works. Detect clicks by repeat rate, change of frequency is not in a fixed pattern. Whistle frequency change in a consistent pattern
Q1: TOPIC. D, E is close in the words used. But E is correct.
D: present information about a problematic issue in environment of particular animal.
E: explain the method used for a problematic issue in particular environment.
Q2. what is correct about whistle and clicks.作者: 胡子长了 时间: 2010-8-18 11:10
V2
一種動物還是烏模仿人說話的問題。
第一段：starling(歐掠鳥)這種鳥可以模仿和vocalize。但是因為它們flock and vocalize too much, too frequently, too.... 所以science studies很少。 最近剛做了一個實驗， 說明starling不僅模仿自然界的聲音，還模仿人的聲音。
第二段：說這個實驗。把幼鳥分成組，只跟人關在一起。發現那組人說話的多，那一組的鳥vocalize就多。 說明幼鳥是通過人的話來學習發音的。而且幼鳥還都模仿
discourse和phrase， 不是單個的word。又說自然界，幼鳥是通過學習neighbor的鳥，比如自己的parents and ...。
第三段，忘了，沒題。作者: 胡子长了 时间: 2010-8-18 11:14
V3
關於starling---八哥的研究，這是一種叫聲音域(compass)很寬的的鳥，甚至與模仿人的聲音（鳥類中的和旋手機），說得是以前很少有這方面的研究（有題），因為需要大範圍，長時間的研究，而這通常做不到。然後說現在通過實驗可以做到。。據了一個可行的例子證明瞭八哥可以通過和人的接觸（有題）就會模仿人的聲音。所以得出一個結論，八哥小時候就開始接受家庭的音樂薰陶了（有題）。
題目：
1）主題題：describe an experiment researching a phenomenon（我選的， 還有一個選項比較模糊，建議大家再看看）
2）如果下面哪個成立，說明這個實驗沒道理？ （感覺像邏輯）
在幼鳥即使在人一句話都沒說的那組，一樣能學會發音。
3）在wild的情況，幼鳥如何vocalize. 答：學習他們的parents and sibling
4) 為什麼科學研究會少？ 答：
(1)因為flock and vocalize too much, too frequently
(2)因為需要大範圍，長時間的研究，而這通常做不到。然後說現在通過實驗可以做到
(疑似)原文未缩减 gitarrelieber
节选自Social influences on vocal development (@ Cambridge University Press 1997)
Author: Charles T. Snowdon, Martine Hausberger
The vocal talent of starlings has been known since antiquity, when Pliny considered their ability to mimic human speech noteworthy. Ornithologists know that this species possesses a rich repertoire of call and songs, composed of whistles, clicks, snarls, and screeches. In addition, starlings are well known for their ability to mimic the sounds of other animals or even mechanical noises. Descriptions of starling song in the past reflect the difficulty of describing all the variety of sounds included. Witherby mentioned a “lively rambling melody of throaty warbling, chiring, clicking and gurgling notes interspersed with musical whistles and pervaded by a peculiar creaking quality.”
This complexity explains why detailed studies of starling song have delayed long after the arrival of the sound spectrograph. As mentioned by West & King, “the problem with starlings is that they vocalized too much, too often and in too great numbers, sometimes in choruses numbering in the thousands. Even the seemingly elementary step of creating an accurate catalogue of the vocal repertoire of wild starlings is an intimidating task because of the variety of their sounds.”
Chaiken have compared the sons of young males raised in different social conditions: either with a wild-caught adult song tutor, individually housed but tape-tutored by a tape-recording or raised in total isolation. All birds had been taken from the nest at an early age (8-10 days) and were hand raised. Untutored birds produced mostly an abnormal song, where even the basic organization of song was missing. In contrast, both tape- and live-tutored birds developed songs with a normal basic organization, but with some syntactical abnormalities for the tape-tutored birds. Tape-tutored birds had repertoires half as large as those of live-tutored birds. Large differences occurred between both groups of birds in their …作者: 胡子长了 时间: 2010-8-18 11:15
后两段原文 gitarrelieber
第二段：A few years ago, Jarvis and his colleagues made the surprising discovery that when a songbird, parrot or hummingbird is producing its learned vocalization, a set of seven similar structures in the birds’ brains become active. The finding was unexpected because the three avian groups are only distantly related to one another. At the same time, they are closely related to other birds that are not vocal learners. Flycatchers, for example, belong to the same order as songbirds—Passeriformes—yet no flycatcher species tested so far displays the trait. One possible explanation, says Jarvis, is that the three groups of vocal learning birds had a common ancestor that possessed the skill. “But this means there would have been multiple losses of the ability over time, a sort of mass extinction of vocal learning,” he says. Another hypothesis is that vocal learners evolved similar brain structures independently over the last 65 million years, much the same way that birds and bats separately evolved wings that turned out to be so much alike.
第三段：Discoveries about the human brain support this latter hypothesis. Scientists conducting imaging studies have found that when people speak, parts of their brains’ cerebrums that are similar to those of vocalizing songbirds, parrots and hummingbirds become active. They’ve also found that the same neural pathways are damaged in people who have lost the ability to speak due to injury or stroke. Jarvis now believes that vocal learning most likely developed independently in humans and the three bird groups (as well as in other learners whose brains have not been studied)—yet it arose from a pre-existing brain system, probably shared by all vertebrates, that controls learning to move.作者: 胡子长了 时间: 2010-8-18 11:16
2.1.10. 是否开发一种vaccine**
V1 无法阻挡的兔子
Para1: 最近有一个debate讨论是否应该develop a vaccine来应对a disease caused by a kind of bacteria. 但是由于这个disease的symptom主要是caused by the immune system, 所以since the risk of provoking reactions is not fully understood, 不建议用这个vaccine。 而且，由于这个病的危害程度不大，人们对于这个vaccine会引起的harmful reaction的tolerance（容忍度）就会小。 Moreover，有另外一种病危害程度比这个病的危害程度更大，而且还是由同一种bacteria引起的，但是针对这个病的vaccine已经逐渐out of market (总之这一段就在反对develop the vaccine)
Para 2: However, in the infested area, among the people who have the highest risk to affected with the bacteria, 生了这种病以后会残疾的可能性很高，而且经过很长一段时间的治疗还是不能恢复。yet，是否是由于这种病而导致的残疾确实不确定的。 but，由于这个残疾的严重性，所以我们应该在这些高危人群中使用 the vaccine作者: 胡子长了 时间: 2010-8-18 11:18
文言文 nowwsy 好古文在上，故此处只留题目
1 如果这个疾病是fatal的话会怎么样：文章认为这个病不是fatal，所以一开始要不要研制疫苗值得考虑
2 主旨题：list factors for and against of (是否开发疫苗)
3 这个VACCINE会引起某些人怎么样 两个答案比较混淆：让他们的免疫系统出现问题 or 会让那些过敏的人产生某种symptom作者: 胡子长了 时间: 2010-8-18 11:18
文言文 Golden 因为蓝字，自行确认
第一段：自然界存在一种现象，蝙蝠在幼小的时候会吃一种难吃的蛾子，然后形成习惯，以后就不吃了。 某专家对其进行了研究。然后说了某专家的研究
第二段：介绍某专家的研究。专家从小把蝙蝠抓起来养着，从而杜绝其在野外的捕食行为。蝙蝠在5天内学会了避免难吃得虫子。还做了一些观察和研究。。做了moth和bat之间反应的试验，第一次有了acoustic confirmation作为模拟防御方面的例子；
第三段：介绍了两个实验：1、把蝙蝠放在一个容器里。让他们吃不好吃得蛾子。这种蛾子叫tiger moth，他们的味道比较糟糕unpalatable，结果蝙蝠在尝过它们的糟糕味道后对tiger moth的clicking产生了抵触，觉得不好吃就不吃了。。接着把本身也是unpalatable但本身不会发出声音的moth和蝙蝠关在一起，就一两只蝙蝠吃。2、换一种美味palatable的蛾子，但是这种蛾子能够模拟tiger moth的声音clicking，结果只有两三只bat上去尝试吃了一下发现它可以吃，其他的bat还是不吃。。
第四段：根据此实验推出了两个结论。因为蝙蝠将这种clicking和tiger moth联系起来之后，不再捕食发出这种clicking的蛾子，而这知识在蝙蝠中广泛流传。后来，其它的蛾子也学会了这种clicking，得以从蝙蝠的口中逃生。两个实验结果发现moth主要靠mimic 声音来defend 天敌。
1、主旨题
2、infer 题，选了那个野外那种能吃又能发吃nazhongclick的蛾子可能很少被吃。
3、analog comparison 题，第二个实验类似于什么，选的是一种蛇没有毒会模仿眼睛王蛇的花纹的动作吓跑敌人。
4、题目有一个比较搞，说是该科学家的试验证明了什么。有个说confirmed the reports of acoustic defensive phenomenon 。还有个说give evidence that defensive phenomenon could be acoustic 。纠结很久选了第二个，因为怎么都没看到文章中提到reports啊
Background文档有背景，非原文作者: 胡子长了 时间: 2010-8-18 11:19
2.2. Geography & Geology
2.2.1. ★火山熔岩的来由
V1 duke3d001 750, wade777, echosweet 700 & yueqianchen
关键词：45KM, Olivine, Orthopyroxene (referenced by gitarrelieber)。这篇文章的题目不难，狗的骨架也很清晰。
第一段讲火山爆发来源于Mantle中的Lava，而Lava来源于Melt ，Melt在向地表上升的过程中会与Mantle中的Rock反应并不断互相交换物质、变化结构，即吸收Orthopyroxene并排出Olivine。
第二段说一个跟理论不太相符的事情，一种海底里的lava sample，在距离地表45千米突然发现已经停止这种物质交换，Melt的结构不变了。一种假设是那里的Mantle太松散了，使Melt无法与他们接触并交换物质，但立即被否定了(因为45KM还很深东西都很软，没有裂缝)。另一种假设是Melt在之前的上升过程中已经吸收了足够的Orthopyroxene， 并将能排出的Olivine都排了，无法继续反应。
1 darkchoco 710是什么可以证明这种exchange的存在：熔岩的成分
2 gyz12 740 一道文章最后句定位：Olivine的用完了,exchange就停止了
3 gyz12 740 一道是选chemical composition为特征 sashimiyuki 720 V37 选“lab experiments” indicate 那个melt 的变化的，没有选chemical composition, 细节题定位后决定的，确认后到现在还没有深深后悔过
4 tianmo0512 是什么发生反应：选melt
5 feifeizoe 750 V39 文中什么情况下描述了那种正常的exchange：lab experiment中实现了那种现象
6 The author mention “the melt to rise so rapidly” in order to：提出了一种hypothesis，这种hypothesis在后面被反驳作者: 胡子长了 时间: 2010-8-18 11:19
(疑似)原文未缩减 gitarrelieber
节选自The Origin of the Land under the Sea (Scientific American Magazine @ February 2009)
Author: Peter B. Kelemen
Knowledge of the intense heat and pressure in the mantle led researchers to hypothesize in the late 1960s that ocean crust originates as tiny amounts of liquid rock known as melt—almost as though the solid rocks were “sweating.” Even a minuscule release of pressure (because of material rising from its original position) causes melt to form in microscopic pores deep within the mantle rock. Explaining how the rock sweat gets to the surface was more difficult. Melt is less dense than the mantle rocks in which it forms, so it will constantly try to migrate upward, toward regions of lower pressure. But what laboratory experiments revealed about the chemical composition of melt did not seem to match up with the composition of rock samples collected from the mid-ocean ridges, where eruptedmelt hardens. Using specialized equipment to heat and squeeze crystals from mantle rocks in the laboratory, investigators learned that the chemical composition of melt in the mantle varies depending on the depth at which it forms; the composition is controlled by an exchange of atoms between the melt and the minerals that makeup the solid rock it passes through. The experiments revealed that as melt rises, it dissolves one kind of mineral, orthopyroxene, and precipitates, or leaves behind, another mineral, olivine. Researchers could thus infer that the higher in the mantle melt formed, the more orthopyroxene it would dissolve, and the more olivine it would leave behind.(melt上升时， 溶解Ort产生Oli, 所以melt higher， 溶解的Ort越多，产生的/留在身后的Oli也越多) Comparing these experimental findings with lava samples from the mid-ocean ridges revealed that almost all of them have the composition of melts that formed at depths greater than 45kilometers. This conclusion spurred a lively debate about how meltis able to rise through tens of kilometers of overlying rock while preserving the composition appropriate for a greater depth. If melt rose slowly in smallpores in the rock, as researchers suspected, it would be logical to assume that all melts would reflect the composition of the fashallowest part of the mantle,at 10 kilometers or less. Yet the composition of most mid-ocean ridge lavas amples suggests their source melt migrated through the uppermost 45 kilometers of the mantle without dissolving any orthopyroxene from the surrounding rock. But how? （疑大概为狗狗第一段的背景内容）
In the early 1970s scientists proposed an answer: the melt must make the last leg of its upward journey along enormous cracks. Open cracks would allow the melt to rise so rapidly that it would not have time to interact with the surrounding rock, nor would melt in the core of the crack ever touch the sides. Although open cracks are not a natural feature of the upper mantle— the pressure is simply too great—some investigators suggested that the buoyant force of migrating melt might sometimes be enough to fracture the solid rock above, like an icebreaker ship forcing its way through polar pack ice. Adolphe Nicolas of the University of Montpellier in France and his colleagues discovered tantalizing evidence for such cracks while examining unusual rock formations called ophiolites. Typically, when oceanic crust gets old and cold, it becomes so dense that it sinks back into the mantle along deep trenches known as subduction zones, such as those that encircle the Pacific Ocean. Ophiolites, on the other hand, are thick sections of old seafloor and adjacent, underlying mantle that are thrust up onto continents when two of the planet’s tectonic plates collide. A famous example, located in the Sultanate of Oman, was exposed during the ongoing collision of the Arabian and Eurasian plates. In this and other ophiolites, Nicolas’s team found unusual, light-colored veins called dikes, which they interpreted as cracks in which melt had crystallized before reaching the seafloor. The problem with this interpretation was that the dikes are filled with rock that crystallized from a melt that formed in the uppermost reaches of the mantle, not below 45 kilometers, where most mid-ocean ridge lavas originate. In addition, the icebreaker scenario may not work well for the melting region under mid-ocean ridges: below about 10 kilometers, the hot mantle tends to flow like caramel left too long in the sun, rather than cracking easily.
To explain the ongoing mystery, I began working on an alternative hypothesis for lava transport in the melting region. In my dissertation in the late 1980s, I developed a chemical theory proposing that as rising melt dissolves orthopyroxene crystals, it precipitates a smaller amount of olivine, so that the net result is a greater volume of melt. Our calculations revealed how this dissolution process gradually enlarges the open spaces at the edges of solid crystals, creating larger pores and carving a more favorable pathway through which melt can flow. As the pores grow, they connect to form elongate channels. In turn, similar feedbacks drive the coalescence of several small tributaries to form larger channels. Indeed, our numerical models suggested that more than 90 percent of the melt is concentrated into less than 10 percent of the available area. That means millions of microscopic threads of flowing melt may eventually feed into only a few dozen, high porosity channels 100 meters or more wide. Even in the widest channels, many crystals of the original mantle rock remain intact, congesting the channels and inhibiting movement of the fluid. That is why melt flows slowly, at only a few centimeters a year. Over time, however, so much melt passes through the channels that all the soluble orthopyroxene crystals dissolve away, leaving only crystals of olivine and other minerals that the melt is unable to dissolve. As a result, the composition of the melt within such channels can no longer adjust to decreasing pressure and instead records the depth at which it last “saw” an orthopyroxene crystal. One of the most important implications of this process, called focused porous flow, is that only the melt at the edges of channels dissolves orthopyroxene from the surrounding rock; melt within the inner part of the conduit can rise unadulterated.作者: 胡子长了 时间: 2010-8-18 11:20
文言文 nowwsy "CO2和气候变冷"前后类似, 只差确认
V1 (综合版)
两段长篇
科学家发现最近40million years，地球不再是原来那么warm和wet了（此处有题），先给出了一个流派的若干解释：随着二氧化碳的增多，大气的降水中融解了二氧化碳，这些水降到海面，被各种过程吸收，然后沉积到海底，虽然到海底这些c最终还是要回到大气中，但是这个过程需要hundreds of millions of years（隐含40百万年对它来说是相对短的过程，此处有题），另外陆面也对二氧化碳的吸收起到一定作用，而且随着内海的面积逐渐减少，陆面的面积越来越大因而吸收c也越多。第一段的末尾说这个解释不错，但作为唯一的解释未免不让人信服。
第二段是讲好像叫M R的人提出一种观点，对第一段的解释起到支持作用，他说地质演变抬高了陆地某些位置，高了之后会有更多的fresh岩石吸收c，而且因为抬高了后这些位置比较陡，降水可以更好的冲走这些吸收了c的岩石。提出的新观点觉得有二个重要原因
a. weathering的过程 （即对第一段的解释起到支持作用）; b. 岩石陆地的上升strengthen了weathering的过程
题目总结：
1．一个题目在第一段，问现在环境跟原来环境有什么区别，选择较Warm, Wet（此题也许是取非题，问现在的环境怎么样，那以前的来取非）
2． 第二段，这个过程（二氧化碳溶解沉入海底再回到大气这个过程）需要hundreds of millions of years（隐含40百万年对它来说是相对短的过程，此处有题）
3． 有一个Except题 （注意第二段中的机理讨论部分，见版本6的总结）
4．然后有一个应该是取非条件的（注意第二段中的机理讨论部分，见版本6的总结）
5．R科学家提出，有逻辑题，以下哪项weaken了R的观点，定位于二段后半部分. 注意R的观点有两个部分 a.weathering的过程 （即对第一段的解释起到支持作用）； b.岩石陆地的上升strengthen了weathering的过程．这题要削弱的应该是第二个观点
6．第二段全划线，机理题作者: 胡子长了 时间: 2010-8-18 11:20
(疑似)原文未删减 gitarrelieber
节选自Plateau Uplift and Climate Change (Scientific American Magazine @ March 1991)
Author：William F. Ruddiman and John E. Kutzbach
During the past 40 million years, and particularly during the past 15 million years, this warm, wet climate largely disappeared. Colder climates and much greater regional extremes of precipitation have developed. What caused this cooling and diversification of climate and vegetation into a complex mosaic of many regionally distinctive types?
One school of thought focuses on the changing positions of the earth’s continents and oceans. The Atlantic Ocean has expanded at the expense of the Pacific Ocean, whereas an ancient equatorial sea that extended across much of Eurasia (called the Tethys Sea) has shrunk to become the modern, much smaller Mediterranean Sea. In addition, the fraction of continents flooded by shallow inland seas has slowly decreased, exposing large amounts of land and creating climates less moderated by the temperature-stabilizing effects of oceans. Computer model simulations show that changes in the arrangement of the continents and the size of inland seas can have important effects on global climate over very long intervals of geologic time. But they are significantly less convincing as sole explanations for the dramatic changes of the past 40 million years.
Another possibility is a long-term decline in the concentration of carbon dioxide in the atmosphere, which would lessen the amount of heat trapped by the atmosphere and lead to “greenhouse cooling.” The amount of carbon dioxide in the earth’s atmosphere over million-year timescales is controlled by two major processes. Chemical weathering of continental rocks removes carbon dioxide from the atmosphere and carries it in dissolved chemical from to the ocean, where it is taken in by marine biota and deposited in sediments on the seafloor. Tectonic activity eventually frees this trapped carbon dioxide, in the earth’s lithospheric plates transports the seafloor to ocean trenches, where subduction carries old crust and sediments down toward the earth’s hot interior. At great depths, the sediments melt, releasing carbon dioxide, which emerges from the volcanic islands that overlie the buried curst and rejoins the atmosphere, completing the cycle.
If the pace of seafloor spreading (and hence of subduction) slowed significantly, less carbon dioxide would be vented to the atmosphere, the atmosphere would become relatively depleted of carbon dioxide and temperatures would fall. In fact, globally averaged seafloor spreading rates slow little or no net change in the past 40 million years. Subduction and volcanism eventually return the carbon dioxide to the atmosphere, but this process requires a long time (tens to hundreds of millions of years) to complete.
Plateau uplift may alter climate by increasing chemical weathering of rocks, thereby reducing atmospheric carbon dioxide concentrations. Carbon dioxide combines with rainwater and ground water to form carbonic acid, which reacts with silicate minerals in rocks during weathering. The resulting bicarbonate ions drain into the oceans, where they are taken up by marine animals such as plankton and corals and eventually deposited on the seafloor. The net effect is that chemical weathering removes carbon dioxide from the atmosphere and locks it away at the bottom of the oceans.
Maureen Raymo proposed that uplift of plateaus and mountain ranges has increased the rate of chemical erosion of continental rock on the globally averaged basis. Uplift could enhance chemical weathering in several ways. Heavy monsoons, which develop at the margins of plateaus, unleash particularly intense rainfall. In these regions, uplift-related faulting and folding also expose fresh rock to the weathering process. Moreover, the steeper slopes created by plateau uplift cause faster runoff, which removes erosion products and intensifies the chemical attack on the rock. Raymo suggests that long-term uplift in Tibet and other regions may have increased the rate at which carbon dioxide is removed from the atmosphere. In this way, concentrations would have fallen even though the amount of carbon dioxide exhaled by volcanoes (as inferred from seafloor spreading rates) remained nearly constant. Falling carbon dioxide levels would reduce the ability of the atmosphere to retain heat, thereby amplifying the global cooling.作者: 胡子长了 时间: 2010-8-18 11:20
(疑似)原文未缩减 gitarrelieber
摘自Scientific American @ Jan 1990
The Yugoslav astronomer Milutin Milankovitch refined and formalized the hypothesis in the 1920’s and 1930’s.The astronomical pacemaker he advocated has three components, two that change the intensity of the seasons and a third that affects the interaction between the two driving factors. The first is the tilt of the earth’s spin axis. Currently about 23.5 degrees from the vertical, it fluctuates from 21.5 degrees to 24.5 degrees and back every 41,000 years. The greater the tilt is, the more intense seasons in both hemispheres become: summers get hotter and winter colder.
The second, weaker factor controlling seasonality is the shape of the earth’s orbit. Over a period of 100,000 years, the orbit stretches into a more eccentric ellipse and then grows more nearly circular again. As the orbital eccentricity increases, the difference in the earth’s distance from the sun at the orbit’s nearest and farthest points grows, intensifying the seasons in one hemisphere and moderating them in the other. (At present the earth reaches its farthest point during the Southern Hemisphere winter; as a result, southern winters are a little colder – than their northern counterparts.)
A third astronomical fluctuation governs the interplay between the tilt and eccentricity effects. It is the precession, or wobble, of the earth’s spin axis, which traces out a complete circle on the background of stars about every 23,000 years. The precession determines whether summer in a given hemisphere falls at near or a far point in the orbit– in other words, whether tilt seasonality is enhanced or weakened by distance sesonablity. When these two controllers of seasonality reinforce each other in one hemisphere, they oppose each other in the opposite hemisphere.
Milankovitch calculated that these three factors work together to vary the amount of sunshine reaching the high northern latitudes in summer over a range of some 20 percent – enough, he argued, to allow the great ice sheets that advanced across the northern continents to grow during intervals of cool summers and mild winters. For many years, however, the lack of an independent record of ice-age timing made the hypothesis untestable.
In the early 1950’s Cesare Emiliani produced the first complete record of the waxings and waning of past glaciations. It came from a seemingly odd place, the sea floor. Single-cell marine organisms called foraminifera house themselves in shells made of calcium carbonate. When the foraminifera die, sink to the bottom and contribute to these a-floor sediments, the carbonate of their shells preserves certain characteristics of the seawater they inhabited. In particular, the ratio of a heavy isotope of oxygen (oxygen 18) to ordinary oxygen (oxygen 16) in the carbonate preserves the ratio of the two oxygen atoms in the water molecules.
It is now understood that the ratio of oxygen isotopes in seawater closely tracks the proportion of the world’s water that is locked up in glaciers and ice sheets. A kind of meteorological distillation accounts for the link. Water molecules containing the heavier isotope tend to condense and fall as precipitation a tiny bit more readily than molecules containing the lighter isotope. Hence, as water evaporated from warm oceans moves away from the source, its oxygen 18 preferentially returns to the oceans in precipitation. What ultimately falls as snow on ice sheets and mountain glaciers is relatively depleted of oxygen 18. As the oxygen 18-poorice builds up, the oceans become relatively enriched in the isotope. The larger the ice sheets grow, the higher the proportion of oxygen 18 becomes in seawater – and hence in the sediments.
Analyzing cores drilled from seafloor sediments, Emiliani found that the isotopic ratio rose and fell in rough accord with the cycles Milankovitch had predicted. A chronology for the combined record showed in 1976 that the record contains the very same periodicities as the orbital process.
……
Others have found that during the last ice age the earth’s mountain glaciers also expanded. The evidence – from the heaps of debris plowed up by the glaciers, knows as moraines – is as clear in the tropics and the southern temperate latitudes. On all the mountains studied so far, regardless of geographic setting or precipitation rate, the snow line descended by about one kilometer, corresponding to a drop in temperature of about five degrees Celsius.
Where organic material was trapped in the moraines, radio carbon dating shows that the glaciers advanced and retreated on the same schedule. They fluctuated near their maximum extent between about 19,500 and 14,000 years ago, about the same time as the glaciations of northern ice sheets began to shrink, the mountain glaciers underwent a dramatic retreat that sharply reduced their size by about 12,500 years ago.
How could changes in summer sunshine at the latitude of Iceland have caused glaciers to grow and retreat in New Zealand and the southern Andes? If orbital cycles do indeed drive glacial cycles by acting directly on northern ice sheets, the response to seasonality changes in the high northern latitudes must be strong enough to override the effects of the very different changes in the Southern Hemisphere. One possibility is that the northern ice sheets themselves translate Northern Hemisphere seasonality into climatic change around the world.作者: 胡子长了 时间: 2010-8-18 11:21
(疑似)原文未缩减 gitarrelieber
节选自Global Climate Change on Venus (New Light on the Solar System; Special Editions)
Author: Mark A. Bullock and David H. Grinspoon
THE STUNNING DIFFERENCES between the climates of Earth and Venus today are intimately linked to the history of water on these two worlds. Liquid water is the intermediary in reactions of carbon dioxide and surface rocks that can form minerals. In addition, water mixed into the underlying mantle is probably responsible for the low-viscosity layer, orasthenosphere, on which Earth’s lithospheric plates slide. The formation of carbonate minerals and their subsequent descent on tectonic plates prevent carbon dioxide from building up. Models of planet formation predict that the two worlds should have been endowed with roughly equal amounts of water, delivered by the impact of icy bodies from the outer solar system. But, when the Pioneer Venus mission went into orbit in 1978, it measured the ratio of deuterium to ordinary hydrogen within the water of Venus’s clouds. The ratio was an astonishing 150times the terrestrial value. The most likely explanation is that Venus once had far more water and lost it. When water vapor drifted into the upper atmosphere, solar ultraviolet radiation decomposed it into oxygen and either hydrogen or deuterium. Because hydrogen, being lighter, escapes to space more easily, the relative amount of deuterium increased. Why did this process occur on Venus but not on Earth? In 1969 Andrew P. Ingersoll of the California Institute of Technology showed that if the solar energy available to a planet were strong enough, any water at the surface would rapidly evaporate. The added water vapor would further heat the atmosphere and set up what he called the runaway greenhouse effect. The process would transport the bulk of the planet’s water into the upper atmosphere, where it would ultimately be decomposed and lost. Later James F. Kasting of Pennsylvania State University and his co-workers developed a more detailed model of this effect. They estimated that the critical solar flux required to initiate a runaway greenhouse was about 40 percent larger than the present flux on Earth. This value corresponds roughly to the solar flux expected at the orbit of Venus shortly after it was formed, when the sun was 30 percent fainter. An Earth ocean’s worth of water could have fled Venus in the first 30 million years of its existence. A shortcoming of this model is that if Venus had a thick carbon dioxide atmosphere early on, as it does now, it would have retained much of its water. The amount of water that is lost depends on how much of it can rise high enough to be decomposed—which is less for a planet with a thick atmosphere. Furthermore, any clouds that developed during the process would have reflected sunlight back into space and shut off the runaway greenhouse. So Kasting’s group also considered a solar flux slightly below the critical value. In this scenario, Venus had hot oceans and a humidstratosphere. The seas kept levels of carbon dioxide low by dissolving the gas and promoting carbonate formation. With lubrication from water in theasthenosphere, plate tectonics might have operated. In short, Venus possessed climate-stabilizing mechanisms similar to those on Earth today. But the atmosphere’s lower density could not prevent water from diffusing to high altitudes. Over 600 million years, an ocean’s worth of water vanished. Any plate tectonics shut down, leaving volcanism and heat conduction as the interior’s ways to cool. Thereafter carbon dioxide accumulated in the air.
This picture, termed the moist greenhouse, illustrates the intricate interaction of solar, climate and geologic change. Atmospheric and surface processes can preserve the status quo, or they can conspire in their own destruction. If the theory is right, Venus once had oceans—perhaps even life, although it may be impossible to know.作者: 胡子长了 时间: 2010-8-18 12:06
V3 chunxia193
第一段拿了很多别的生物生产的能量的数字来比较，得出藻类是生产得最多的。这有题：题目列举数字比较的目的是啥，我选的是为了explain the increasing interet on new source（反正大概这个意思，可能我用的词和选项不是exactly the same）；
第二段说利用这种藻类的优点，比如不需要太多空间，放个装藻类的大水箱（tanker）在power plant旁边就可以吸收燃烧废气什么的。关于海藻空间有题：问文章的作者可能会同意以下哪种说法：我选的是种植海藻不需要和其他作物抢占农田。其中一个选项是说海藻需要保持warm的温度，注意了，文中是说海藻是需要stable的温度，没有warm也没有cool。
文言文 Golden 自己考古以前考过的题，大家来确认
V1 Golden 540 V14
第一段貌似是说藻类可以对工业有益的，然后说可以利用这种藻类的特性用来协助工业的制造（吸收CO2）。
第二段说利用这种藻类的优点，比如不需要太多空间，放个装藻类的大水箱（tanker）在power plant旁边就可以吸收燃烧废气什么的。
第三段说这种藻类的Weaknesses和用在工业上需要注意的地方，貌似对温度的要求比较严格等等... 其他记不住了~
有题问利用这种海藻的苛刻条件的好像作者: crystalbain 时间: 2010-8-21 07:55
谢谢分享!1
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