Question

When Tom got to the examination room, he realized he ______ his pen at home.

A．was leaving

B．had left

C．forgot

D．was forgetting

Answer 1

B

试题分析：句意为：汤姆一进入考试室就意识到了他把笔落在家里了。根据语境，这是一个发生在“过去的过去”（即意识到之前）的一个动作，因此要用过去完成时。故选B。