in a week还是after a week

问题描述

—Where is your aunt?

—She went to Beijing last month. She will be back _______ a week.

A. after   B. in    C. behind   D. later

我在 after 和 in 中犹豫。 

老师答疑

陈老师：

—Where is your aunt?

—She went to Beijing last month. She will be back _______ a week.

A. after         B. in         C. behind         D. later

答案应是 in，表示“一周之后”。关于after与in 的区别，请参考英语语法网《介词after与in的区别》