白勇语法书上的题，请帮忙

白勇语法书P330－50

In the mid-1920's the Hawthorne Works of the Western Electric Company was the scene of an intensive series of experiments that would investigate changes in working conditions as to their effects on workers' performance.

A)    that would investigate changes in working conditions as to their effects on workers'performance

B)     investigating the effects that changes in working conditions would have on workers]performance

C)    for investigating what are the effects in workers'performance that changes in working conditions would cause

D)    that investigated changes in working conditions'effects on workers'performance

E)     to investigate what the effects changes in working conditions would have on workers'performance

答案B。这道题没有任何思路，看书中解释也很糊涂。请大家帮忙分析一下。谢谢！

你是那个版本的 白勇的语法 是黄色封面的那个 2006年8音第二版吗？没有这一题，按你说的页数。

以下是引用mattus在2007-4-12 19:09:00的发言：
说实话，没思路…

怎么会呢？这曾经是GWD争议题，而且PREP-SC也有这题（第157题）。

答案是B没问题，虽然B看上去一团乱，但事实上很清楚，读一下意群。investigating是分词作experiment的后置定语，effects是investigating的宾语，后跟定语从句修饰effects。

B. investigating the effects that changes in working conditions would have on workers’ performance

effects在定语从句中充当宾语成分，have (effects) on...选项还是挺乱的...肯定这题碰到吐一地...

谢谢各位！能不能烦请大牛翻译一下这个句子，可能有助于对结构的理解。

In the mid-1920's the Hawthorne Works of the Western Electric Company was the scene of an intensive series of experiments 
   investigating the effects that changes in working conditions would have on workers' performance.

在20世纪20年代中期，HWWEC呈现给世人的是他是一系列缜密的关于工作条件上的变化给工人们的生产活动所造成的影响的试验的依托者。

在1920年代中期，霍桑试验呈现了一系列精密的试验，试验调查“用改变工作环境来影响工人表现”的效果

注：芝加哥西部电气公司所进行的霍桑实验(The
            Hawthorne
            Works
            of
            the
            Western
            Electric
            Company)

可是为什么...the effects that changes in working ... 是changes而不是chang 呢? effects是复数啊...

  investigating the effects that changes in working conditions would have on workers' performance

that(effects)在定语从句中做宾语，changes是定语从句主语，不是定语从句谓语