求教Prep 1-Essay #15

meckychen

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 #50.341-02(23608-!-item-!-188;#058&000341-02)

The passage suggests which of the following about the ring patterns of two trees that grew in the same area and that were of different, but overlapping, ages?

(A) The rings corresponding to the overlapping years would often exhibit similar patterns.

(B) The rings corresponding to the years in which only one of the trees was alive would not reliably indicate the climate conditions of those years.

(C) The rings corresponding to the overlapping years would exhibit similar patterns only if the trees were of the same species.

(D) The rings corresponding to the overlapping years could not be complacent rings.

(E) The rings corresponding to the overlapping years would provide a more reliable index of dry climate conditions than of wet conditions.

答案是A，why？
原为定位在哪里呢？请高手相助。
谢了。

roddysong

定位在Often, ring pattrns of dead trees of different, but overlapping, ages can be correlated to provide an extended index of past climate conditions.
我用的是排除法

(A) The rings corresponding to the overlapping years would often exhibit similar patterns.

(B) The rings corresponding to the years in which only one of the trees was alive would not reliably indicate the climate conditions of those years
没说树的死活问题
(C) The rings corresponding to the overlapping years would exhibit similar patterns only if the trees were of the same species.没说要同种类才行

(D) The rings corresponding to the overlapping years could not be complacent rings.定位的那句话没说complacement rings.


(E) The rings corresponding to the overlapping years would provide a more reliable index of dry climate conditions than of wet conditions无关比较

lxw19

还是不太懂这道题~~那位大牛进来帮着解答一下啊~~先谢啦

aomeisoft7

还是不太懂这道题~~那位大牛进来帮着解答一下啊~~先谢啦

-- by 会员 lxw19 (2010/9/17 20:20:17)

Often, ring patterns of dead trees of different, but overlapping, ages can be correlated to provide an extended index of past climate conditions.
我的理解是：
经常，死去的不同年龄的树，但是在一个时间段里曾共同生存过，那么这段时间里生长的树年轮是具有相似特征的，这个特征提供了更多的可靠的过去气候的信息


简而言之，不同的树，年轮有相同特征，能可靠推测其生存时的气候
即选项A

lxw19

谢谢ls  明白了哈~~

michaelyueyue

我觉得大家CDE是直接可以排除的选项。
而AB的话，B有点否命题的感觉，就是原文说了重叠的时期是可以带来更多信息，但没说没重叠的时间带来的信息就“不可靠”了