Question

Mr. Green his lessons when I went into ...

Mr. Green his lessons when I went into his office. A．prepares B．prepared C．is preparing D．was preparing

Answer 1

D

试题分析：句意为：我进到办公室的时候，格林先生正在备课。本句表示的是过去某一时刻正在进行或发生的动作，应用过去进行时。故选D。