四六级考试

【单选题】 The students ______ busily when Miss Brown went to get a book she ______ in the office.
A．had written, left
B．were writing, has left
C．had written, had left
D．were writing, had left

网考网参考答案：D
网考网解析：
[分析] 此题考查时态。“把书忘在办公室”发生在“去取书”这一过去的动作之前，因此“忘了书”这一动作发生在过去的过去，用过去完成时。 查看试题解析出处>>