He seldom speaks English after class,for he is afraid __ mistakes __ grammer.

题目

He seldom speaks English after class,for he is afraid __ mistakes __ grammer.
A.to make;of B.making;of C.to be made;in D.of making;in

答案

D
be afraid of doing sth 担心会发生某事
be afraid to do sth 害怕做某事
翻译：他课后很少讲英语,因为他担心会犯语法错误.
in grammar 在语法方面.