reciprocate: implies a more or less equivalent exchange or a paying back of what one has received: ~ their hostility by inviting them for a visit.


retaliate: usually implies a paying back of injury in exact kind by way of vengeance: the enemy ~d by executing their prisoners.  （vengeance报复报仇复仇，较正式refers to the formal act of punishing or harming someone in return for what they have done to you，如a desire for vengeance复仇心，to take vengeance on someone对某人进行报复，如he swore vengeance on his child's killer他发誓要找杀害他孩子的凶手报仇，这个词还表示强烈猛烈，如it began to rain again with a vengeance又开始下起了瓢泼大雨，如she set to work with a vengeance她加倍努力地工作起来）


requite: implies a paying back according to one's preference and often not equivalently: ~ed her love with cold indifference.


return: implies a paying back of something usually in kind but sometimes by way of contrast: ~ed their kindness with ingratitude.


reciprocate回报: 指相等回报，或归还，retaliate报复: 指以同样的伤害回报伤害，requite回报: 表示按意愿，可能不等价，return回报: 既可指回报相同的事物也可指相反的事物


记忆方法: 1）首字母4R想成所有人<==回报     "报"的原意是"治人之罪"，即制服判决罪人，因为需要上报所以引申出了"报告，即让人知道"的意思。古文左边是刑具，右边是一个人，由于字形一直变化，已经看不出来这个意思了

         2）回报的意思是返还同等类型数量mean to give back usually in kind or in quantity.    in kind以同样的方式with something of the same kind，如she pays him back in kind她用同样的方式回报他