I___________ frustrated when I wasn’t sure of the correc Wap版

试题详情及答案解析

I___________ frustrated when I wasn’t sure of the correct answer.

A．may be	B．used to
C．used to be	D．use to be

答案：C

试题分析：句意：当我不能确定正确答案时，我很沮丧。used to be过去常常。结合句意，故选C
考点：考查动词的用法。