---Are you free after school?
---Sorry, I’ve planned to treat a friend of mine to dinner for his help.
A. in trouble
B. in fact
C. in total
D. in return
网友回答
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。