The students busily when Miss Brown went to get a book she in the office.A. had written

问题补充：

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

答案：

A. had written; left

B. were writing; has left

C. had written; had left

(答案→)D. were writing; had left

解析：考查时态。句意：当布朗小姐去取落在办公室的书的时候，学生们正忙于写作业。故第一空用过去进行时，第二空用过去完成时。选D。