Question

The students ________ busily when Miss Brown went to get a book that she ________ in the office.

[　　]

A．had written; left

B．were writing; has left

C．had written; had left

D．were writing; had left

Answer 1

答案：
解析：

本题考查谓语动词的时态。从busily一词和when引导的时间状语可知，学生们“正在忙于写字”，故第一空要用进行时。而“书忘在办公室”的动作发生在写字之前，故用完成时。