问题补充：
He’s given me so much help that I really want to do something for him .
A. in turn
B. by turns
C. in return
D. in answer
答案：
A. in turn
B. by turns
(答案→)C. in return
D. in answer
解析：本题大意，他已经给了我如此多的帮助，以至于我想为他做点事情作为回报。A. in turn 依次，轮流 B. by turns 轮流地 C. in return 作为报答 D. in answer与to连用构成短语，回答、应答、响应。
考查点：短语辨析
