– Are you free after school?-- Sorry. I’ve planned to treat a friend of mine to dinner fo

问题补充：

– Are you free after school?

-- Sorry. I’ve planned to treat a friend of mine to dinner for his help.

A. in addition

B. in turn

C. in return

D. in total

答案：

A. in addition

B. in turn

(答案→)C. in return

D. in total

解析：考查介词短语辨析。A另外；而且；B依次；轮流；C作为回报；D总共，共计；句意：—放学以后你有空吗？—对不起。作为对我的朋友帮助我的回报，我计划请这个朋友吃饭。根据句意说明C正确。