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

问题补充：

The boys 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：短语辨析。in turn 轮流；依次；相应的；按着一定的顺序进行；at turns 在转弯处；by turns 轮流，交替；in turns没有这个说法。 句意：这个男孩对其他人很不礼貌，相应的这也伤害了他自己。结合语境前后动作为一定的顺序，故选A。