The boy is impolite to others and this hurts himself.A. in turnB. at turnsC. by turnsD. i

问题补充：

The boy is impolite to others and this hurts himself.

A. in turn

B. at turns

C. by turns

D. in turns

答案：

(答案→)A. in turn

B. at turns

C. by turns

D. in turns

解析：in turn轮流，依次，反过来(按着一定的顺序进行)；by turns 轮流(一种交替的寓意)；in turns依次，替换地(但是不常用)。句意：这个男孩对他人不礼貌，这样反过来也伤害了自己。