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 knocki

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

试题答案

C