After seemed like hours he came out with a bitter smile.A. which 　B. itC. what　D. that

问题补充：

After seemed like hours he came out with a bitter smile.

A. which

B. it

C. what

D. that

答案：

A. which

B. it

C. what

D. that

解析：

其余三项都很容易误选。误选A，认为介词后应接关系代词which（但是，若填关系代词，其前没有先行词）；B或D也不能选择，因为介词后可接what引导的宾语从句，但通常不能跟that引导的宾语从句或没有引导词的从句。另一方面，引导名词性从句的that也不能充当句子成分(句中的seemed缺主语)。选C，what引导的是宾语从句，用做介词after的宾语，其中的what可理解为some time that。