题干

The students ____ busily when Miss Brown went to get a book she_____ in the office.
A.had written, leftB.were writing, has left
C.were writing, had leftD.had written, had left
上一题 下一题 0.64难度 单项选择 更新时间:2014-12-02 05:44:25

答案(点此获取答案解析)