He( )for six years ,by the time he takes his examination

问题描述:

He( )for six years ,by the time he takes his examination
He( )for six years ,by the time he takes his examination
A had been studying english
B will have been studying english
C studied english
D studies english
请问选什么?

选 B
解题秘诀:
by + 时间 句子用完成时态
句意:截止到他参加考试,他英语学了6年.为什么不选A啊A 是个过去完成,而后面的句子是 一般现在时takes