As I __a letter to my teacher,Robert __to visit me.A was writing;_英语解答

As I __a letter to my teacher,Robert __to visit me.A was writing; came B wrote; came
C was writing; was coming D wrote; was coming

人气：225 ℃　时间：2020-05-28 07:38:06

解答

A这里的as 相当于when ,前面用进行时,后面用一般时啊