老版 prep 17(答案的不对还是我思考的不周全)

sumerlaw

Urban air contains more sulfur dioxide than does rural air, and plants in cities typically grow more slowly than do plants in rural areas.  In an experiment to see how much of the difference in growth is due to sulfur dioxide, classes in an urban and a rural school grew plants in greenhouses at their schools and filtered the greenhouse air to eliminate sulfur dioxide.  lants in the urban greenhouse grew more slowly than those in the rural greenhouse.



Which of the following, if true, would it be most important to take into account in evaluating the result?

B D

(A) The urban school was located in a part of the city in which levels of sulfur dioxide in the air were usually far lower than is typical for urban areas.

(B) At both schools, the plants in the greenhouses grew much more quickly than did plants planted outdoors in plots near the greenhouses.

(C) The urban class conducting the experiment was larger than the rural class conducting the experiment.

(D) Heavy vehicular traffic such as is found in cities constantly deposits grime on greenhouse windows, reducing the amount of light that reaches the plants inside.

(E) Because of the higher levels of sulfur dioxide in the air at the urban school, the air filters for the urban school's greenhouse were changed more frequently than were those at the rural school.

题目问的是评价试验的结果：实验的目的是为了看硫磺对植物的生长造成了多大的影响

D看上去解释了，城市温室里的植物为什么长的慢

但是我感觉无关：1，成立：是由于阳光的原因导致了生长慢。 2，不成立：生长的慢由于他因造成

这两个evaluate 都和硫磺与植物生长的关系无关啊。

只有B给出了评价 1成立：硫磺抑制生长 2：不成立：硫磺与植物生长是独立

哪位大N来评评理？

songer_xj

谢谢楼上各位。相关的好像还有E选项，但E怎么排除？

wemustrun

我也是选B，现在想明白了B实际上是不相关的。而D通过一个全新的原因推出了结论，文中实验结果的原因事实上是缺条件的，也就是说没有光照这个条件是得不出这个实验结果的，根据问题most important to take into account in evaluating the result? 就明白了。

sumerlaw

现在想想知道为什么了，答案是D。

两个植物，一个在农村，一个在城市，都放在温室里，温室里面没硫磺，去除了硫磺这个因数，看生长速度一样不一样，不一样则硫磺对生长没作用，一样则是硫磺导致的
B，温室外面的，因该irrelevant，因为文章比较的两个温室了的植物

D则可以评价

谢谢神灯启发了我

阿拉丁神灯

本题的答案确定为D ，
我的对于这题的分析如下，仅供参考
1. 本题问的是evaluate，所以可以通过对这些选项的是或否，来看削弱或加强与否，（当然这种方法往往是用于不确定时的验证）

2. 本题的结论是plants in cities typically grow more slowly than do plants in rural areas。所以这是一个很典型比较型结果，所以我们的evaluate必须也存在比较，而注意——这是植物的生长在城市和农村的比较，所以我的evaluate需要存在这个元素。

3. 而D，我们可以看到Heavy vehicular traffic 是城市相对独有的，农村相对没有的，而Heavy vehicular trafficsuch 是constantly deposits grime on greenhouse windows，说明这种现象是在城市客观长期存在的，足以代表城市，而最为关键的就是reducing the amount of light that reaches the plants inside. 这里很明确地涉及了一些自然科学原理，因为阳光对于植物生长是会起到足够影响的。所以D在这里等于是提出了他因，除了通过filtered the greenhouse air会让其生长缓慢，阳光也是一个因素。起到了评价的作用。

4. 而B，则显然不存在城市和农村的比较，而且，B只能起到对于filtered the greenhouse air会不会使植物生长缓慢的评价，与题意不符

sumerlaw

看选项，这个是解释题吧。。题干中有矛盾现象要解释。没有什么结论要评价啊。。

-- by 会员 仙蒂瑞拉 (2010/1/1 23:57:19)

可题目说要evaluate啊

仙蒂瑞拉

看选项，这个是解释题吧。。题干中有矛盾现象要解释。没有什么结论要评价啊。。