1. 一个正三角形，三个边的中点连成三条线，每条线都是1，求正三角形的单边边长。 我算出来是2。 2. PS: 有七个数字，media 是10，range是70，最大的三个数的中位数是30，求下列三个数字有哪几个可能是最小三个数的range. I. 0 II. 30 III. 50 其它的大多很简单，现场快速计算就可以求出答案
RC-
1. 讨论美国南北战争(civil war)期间的African American。一或两段，以一个历史学家的观点为主，她与其它的历史学家对黑奴藉由工作累积金钱以购买自由的观点不同，主要是她认为其它有职业的.urbanized的黑人提供了黑奴许多帮助。 最后两句考了supporting ideas, 考这些urbanized的黑人提供黑奴什么样的协助(EXCEPT)。 2. Physic turbulence 以及non-linear equation的本月JJ 3. Futures 讨论房地产与养猪业的本月JJ 4. 讨论共有资源的耗竭问题tragedy，文章不难很好懂。 第一段先说明 tragedy的概念，因为捕鱼没有限额，所以大家都没有限制的捕猎，造成资源的耗竭 第二段举另外一个例子，说明如果是私有财的状况，因为过度使用资源会影响未来收益，因此会小心控制资源。 第三段先说明因此需要政府的力量来进行regulate，然而这会需要许多国家来协议，每个国家都想兼顾自己的利益，所以其实还是很难达成理想个结果。最后只能依靠价格机制，渔获多供给多于消费者需求，则价格下跌，渔民才会少捕鱼。
CR有遇到两题JJ
原题：Q21:
Telomerase is an enzyme that is produced only in cells that are actively dividing. For this reason it is generally absent from body tissues in adults. Bone marrow is an exception to this rule, however, since even in adults, bone marrow cells continually divide to replace old blood cells. Cancers are another exception, because their cells are rapidly dividing.
The information provided most strongly supports which of the following?
A. Telomerase is the only enzyme that is present in cancerous cells but absent from cells that are not actively dividing.
B. In children, the only body tissues from which telomerase is absent are those in which cells are not rapidly dividing.
C. The presence of telomerase in bone marrow is no indication of bone marrow cancer.
D. Cancer of the bone marrow develops more rapidly than cancer growing in any other kind of adult tissue.
E. The level of telomerase production is always higher in cancerous tissue than in noncancerous tissue.
Answer: C
The violent crime rate (number of violent crimes per 1,000 residents) in Meadowbrook is 60 percent higher now than it was four years ago. The corresponding increase for Parkdale is only 10 percent. These figures support the conclusion that residents of Meadowbrook are more likely to become victims of violent crime than are residents of Parkdale.
The argument above is flawed because it fails to take into account
A.Changes in the population density of both Meadowbrook and Parkdale over the past four years.
B.How the rate of population growth in Meadowbrook over the past four years compares to the corresponding rate for Parkdale
C.The ratio of violent to nonviolent crimes committed during the past four years in Meadowbrook and Parkdale
D.The violent crime rates in Meadowbrook and Parkdale four years ago
E.How Meadowbrooks’ expenditures for crime prevention over the past four years compare to Parkdale’s expenditures.
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