GMAT考试语法部分对考生的要求是非常高的，一般能在GMAT语法部分拿到不错的考试成绩的同学往往都有不错的语法基础。语法是很多小知识点的集合，而且有很多的考试常识需要考生们去掌握，小编今天带来的GMAT考试技巧主要告诉大家的是after的使用技巧，一起来看一下吧：
1 after doing 相关问题
220. (GWD-24-8, OG12-86)The results of the company's cost-cuttingmeasures are evident in its profits, which increased five percent during thefirst three months of this year after it fell over the last two years.
A. whichincreased five percent during the first three months of this year after it fell
B. whichhad increased five percent during the first three months of this year after ithad fallen
C. whichhave increased five percent during the first three months of this year afterfalling
D. with a five percent increase during the firstthree months of this year after falling (C)
E. with a five percent increase during the firstthree months of this year after having fallen
答案选C，但解释上有点问题我不明白：下面是语法笔记上对于B和C的解释：
B. after it had fallen时态上没有问题，可以与over the last two years搭配，但是不如after falling简洁
C. Correct;afterfalling简洁，状语从句的省略
求助讨论：可是我不理解为什把after doing理解为状语从句的省略。我觉得这里不是省略!!!
状语从句的省略：从句主语和主句主语一致，并且包含be。。。从句主语和be可以省略。when，although ，等词引导时间状语从句，让步状语从句等时，可以用这种形式来简洁表达。
但是如果把这里的after doing 理解为 after it have/had been falling。我觉得也不能清晰的表达出原文所想表达的时态先后关系。而且如果这里 fall是进行时表达一直在下降，这里也是不对的吧。