问题 选择题

_____ Monday morning he wrote an article on grammar. 

_____ Monday morning he had written an article on grammar. 

A.By

B.On

C.At

D./

答案

答案:B

A.用on(at)+过去时间状语,句子用过去时;by+过去时间状语,句子用过去完成时.

实验题
判断题