Question

【题目】It ________ be the vocabulary that caused you the problem in the exercise because you know a lot of words.

A．may B．couldn't

C．should D．needn't

Answer 1

【答案】B

【解析】考查情态动词表推测的用法。由语境“因为你知道很多词汇”可知，“你练习中的问题不可能是词汇量不够造成的”，故用couldn't表示否定推测，意思是“不可能”。