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。