Question

动词的分类：行为/实义动词、及物与不及物动词、瞬时与持续动词、状态与动作动词、 助动词、情态动词与连系动词

1. There is someone knocking at/on the door. Who ________ it be?

  A) may            B) will            C) can          D) must

Answer 1

C