he did his homework carefully for fear that he

问题描述:

he did his homework carefully for fear that he
He did his homework carefully for fear that he ( ).
A.made a mistake B.makes a mistake C.would make a mistake D.make a mistake
为什么选B 不选C?

因为前面是有for fear 所以后面要接一般现在时态.
那是一种语法规定.