___he entered the university,his english has been much improved.A beforeB afterC whenD since为什么选D,ABC怎么错了?

分类: 作业答案 • 2022-06-12 13:55:50

问题描述：

___he entered the university,his english has been much improved.
A before
B after
C when
D since
为什么选D,ABC怎么错了?

答