Prep1-essay15

msufcufou

Dendrochronology, the study of tree-ring records to glean information about the past, is possible because each year a tree adds a new layer of wood between the existing wood and the bark.
In temperate and subpolar climates, cells added at the growing season's start are large and thin-walled, but later the new cells that develop are smaller and thick-walled; the growing season is followed by a period of dormancy.
When a tree trunk is viewed in cross section, a boundary line is normally visible between the small-celled wood added at the end of the growing season in the previous year and the large-celled spring wood of the following year's growing season.
The annual growth pattern appears as a series of larger and larger rings.
In wet years rings are broad; during drought years they are narrow, since the trees grow less.
Often, ring patterns of dead trees of different, but overlapping, ages can be correlated to provide an extended index of past climate conditions.



However, trees that grew in areas with a steady supply of groundwater show little variation in ring width from year to year; these "complacent" rings tell nothing about changes in climate.
And trees in extremely dry regions may go a year or two without adding any rings, thereby introducing uncertainties into the count.
Certain species
sometimes add more than one ring in a single year, when growth halts temporarily and then starts again.

Question #52.
341-04
(23700-!-item-!-188;#058&000341-04)



The passage is primarily concerned with



(A) evaluating the effect of climate on the growth of trees of different species

(B) questioning the validity of a method used to study tree-ring records

(C) explaining how climatic conditions can be deduced from tree-ring patterns

(D) outlining the relation between tree size and cell structure within the tree

(E) tracing the development of a scientific method of analyzing tree-ring patterns


我选了B，虽然我明白这个"questioning"用的不对，不过总的来说这是一个说明性的文章。
正确答案是C，怎么变成问题解决型了呢？费解

zongzeng90

通篇说的都是气候和外在环境如何影响年轮啊。没有看出其他论点对的地方，除了C。

bettyofariN

questioning为什么不对呢？他的确是提出了这个方法也有uncertainties啊

susander

questioning为什么不对呢？他的确是提出了这个方法也有uncertainties啊
bettyofariN 发表于 2010-8-16 06:39

    阅读有这么一条法则是“末端收敛不改变全文基调”
末句对全文基调的细微改变不能影响全文原意哦~

shlshing

questioning the validity of a method used to study tree-ring records
a method used to study tree-ring records

其实整篇文章只是在介绍年轮和气候有什么联系，从不同的年轮能看出来什么不同的气候，而没有提到用了什么方法来研究年轮：比如说：把树切开直接看还是也要做化学实验分析之类。。。。所以这个选项很有迷惑性。。。我也错了

piggycandys

成吧 我也选B

michael_wind

其实第一段的第一句话，表明作者的态度：认为这个方法是possible的，只是第二段提到了一个例外。总的态度还是肯定的。所以question the validity是不对的。。欧也选错了。