谁能解释一下prep2-15

In the mid-1920s 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 the effects on workers' performance are 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

这题的B是现代分词作定语修饰experiments,但是有个问题，这题的时间是mid-1920s ,怎么会用investigating修饰而不是用that investigated 呢？

(A) their指代不清楚，可能是changes，也可能是conditions；

(D) 表达不清晰，可以理解为changes in… effects，也可以理解为changes in working conditions。

N+doing结构要求doing 的动作发生与主句谓语有同时性，否则不能使用n+doing结构

如：the boy who will come to see you is my son不等于the boy coming to see you is my son

另外有一题为证：OG10-1

The Wallerstein study indicates that even after a decade young men and women still experience some of the effects of a divorce occurring when a child.
A.occurring when a child
B.occurring when children
C.that occurred when a child
D.that occurred when they were children
E.that has occurred as each was a child