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标题: PREP1-17 [打印本页]

作者: zhaoyiqing 时间: 2010-2-23 18:05
标题: PREP1-17

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.Plants 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?

(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.

(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.

为什么A不对呢

作者: zhaoyiqing 时间: 2010-2-23 22:15
求助啊！

作者: gmatziyu 时间: 2010-2-23 23:23
标题: 选Ｄ
这道题讲的是ｇｒｅｅｎｈｏｕｓｅ的试验，外面的空气质量和题目无关。是干扰选项。
应该选Ｄ。因为阳光也是造成ｇｒｅｅｎｈｏｕｓｅ植物生长缓慢的原因。
希望可以帮到你

作者: zhaoyiqing 时间: 2010-2-24 18:46
我也觉得D是对的
但是我觉得sulfur dioxide是影响试验结果的啊如果这个URBAN地区不能代表整个URBAN 那试验结果就不能说明问题啊

作者: slamshady 时间: 2010-4-17 15:06
如果对A做肯定回答，说明即使在sulfur doxide少的地方植物也生长得慢，那更不用说在sulfur dioxide正常水平的地方了，所以无法削弱结论

作者: Souref 时间: 2010-4-19 00:03
只要管大棚里面的条件就好了，大棚外面的就算全是氢气也无所谓啊

作者: gracezz 时间: 2010-5-6 14:36
B呢？B说俩都比在外面长得慢，说明sulfur是对植物生长有影响的呀。这就evaluate了这个结果呀？

作者: gracezz 时间: 2010-5-6 14:40
哦我明白了，村里S少嘛，试验的目的是在城市和村里建立一个相同的环境，这样俩地儿的植物应该长得一样高吧，如果村里的也比原来长得快，那说明除了S还有别的因素使植物也长得慢。。。

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