Mary gave Jack so much help that he gave her some roses for her kindness.A. in turnB. by

问题补充：

Mary gave Jack so much help that he gave her some roses for her kindness.

A. in turn

B. by turns

C. in answer

D. in return

答案：

A. in turn

B. by turns

C. in answer

(答案→)D. in return

解析：四个选项分别表示依次、轮流、回答和作为回报，根据题意选D，玛丽给了杰克这么多帮助，因此作为回报他给了她一些玫瑰花。