求助啊~og13 sentence correction 第90题 with怎么错了？91题更是一片茫然

乖囧猫

如题，OG13 CS里第90题不知道with怎么错了？另外正确选项里的after falling，怎么使用falling？为什么不使用have fallen？
91题更让我不知所措啊。。。哪位大牛能帮小妹解释一下下？
对了，79题的D选项我没看懂解释啊。。。NN能用中文给我解释下么？
谢谢啦！！！

savageprince

before/after后面要跟v-ing形式啊。

花花臭臭

The results of the company's cost-cutting measures are evident in its profits,
{which increased five percent during the first three months of this year after it fell }over the last two years.  

A. which increased five percent during the first three months of this year after it fell
B. which had increased five percent during the first three months of this year after it had fallen
C. which have increased five percent during the first three months of this year after falling
D. with a five percent increase during the first three months of this year after falling
E. with a five percent increase during the first three months of this year after having fallen

jiaoguitar

请LZ贴题先。

sishenguilai

我也是不知道那个falling是怎么回事，也许是根据句意得出的不用have felled 或者 had falled