—Are you free this evening? —Sorry I’ve promised to have Mary’s radio repaired for her h

问题补充：

—Are you free this evening?

—Sorry, I’ve promised to have Mary’s radio repaired for her help with my English.

A. in relief

B. in return

C. in turn

D. in fact

答案：

A. in relief

(答案→)B. in return

C. in turn

D. in fact

解析：考查介词短语辨析。句意：--你今晚有空吗？--对不起，作为玛丽帮我学英语的回报，我已经答应去帮她修理收音机了。A显著地；B作为报答，反过来；C轮流；D事实上。In return for sth作为对......的回报，故选B。