-Are you free after school? ---Sorry I’ve planned to treat a friend of mine to dinnerf

问题补充：

---Are you free after school?

---Sorry, I’ve planned to treat a friend of mine to dinnerfor his help.

A. in trouble

B. in fact

C. in total

D. in return

答案：

A. in trouble

B. in fact

C. in total

(答案→)D. in return

解析：in trouble在麻烦中；in fact事实上；in total总计，总共；in return作为回报。句意：——放学后你有空吗？——对不起，作为对他帮助的回报，我已经计划请我的一个朋友吃饭。