885-S1-18

逻辑上：

housing integration reduces any future need for busing
挺好的呀：因为房子靠近了，所以减少了乘车的需求。

不过也不是很肯定。

因为房子靠近了的情况增加减少了乘车的需求。

好象也能说得通。

http://forum.chasedream.com/dispbbs.asp?BoardID=23&ID=42558

谢谢pumpkin贴出解释
但是这个解释并没有说明A中which指谁呀。

我的想法如下：

如GEMJ所说：
>如果housing integration reduces any future need for busing
>因为房子靠近了，所以减少了乘车的需求。

那我可以变化一下原句：
to significant decreases in housing integration, which, in turn, increases any future need for busing。
这里难道又是因为housing integration增加了乘车的需求？

但从in turn这个词上可以判定，后面一句话是沿着前面的动作变化来的，而变化的中心可以集中到它的宾语上increases in housing integration，但reduces 却是单数形式，5555

如果which指代前面这句话（学校的集中导致房子集中的增加），则没有以上的问题了。

to be discussed.

这才是E答案：School integration plans that involve busing between suburban and central-city areas have contributed, according to a recent study, to significantly increase housing integration, which, in turn, reduce  any future need for busing.

E的解释：In choice E, which clearly refers to housing integration, making the plural verb reduce incorrect. This question is of middle difficulty.

作者在前面说：Choices C, D, and E entail the ungrammatical construction have contributed… to increase.（这些选项认为increase是动词）

他后再说这句话是默认了前面即便没有问题，也就是即便increase是动词，那么也还有这样的指代问题。而E中which只能指代宾语成分housing integration，所以，会出现动词单复问题，所以才会有ETS的解释。