nullify: implies counteracting completely the force, effectiveness, or value of something: his critical insights are ~ied by tiresome puns.    （counteract表示互相抵消implies an opposition between two things that nullifies the effect of one or both，可见counteract和nullify互释，如poor eating habits will have a counteractive effect on any gains from exercise不良饮食习惯会抵消运动带来的好处） nullify常表示废除，如he used his broad executive powers to nullify decisions by local governments他利用自己广泛的行政权力废除当地政府所作的决定   pun双关


negate: implies the destruction or canceling out of one of two mutually exclusive things by the other: a relationship ~ by petty jealousies.  mutually exclusive互相排斥，如True和False是互相排斥的，如果某物是False，就一定不会是True，又如二进制里的1和0也是mutually exclusive，它们的存在都会"negate" the other one(of the two).


annul: suggests a neutralizing or a making ineffective or nonexistent often by legal or official action: the treaty ~s all previous agreements.  


abrogate: is like annul, but more definitely implies a legal or official purposeful act: a law that would ~ certain diplomatic privileges.    可见，表示官方法律的两个词都以a开头


invalidate: implies a making of something powerless or unacceptable by a declaration of its logical or moral or legal unsoundness: the absence of witnesses ~s the will.    （sound合理，指观点意见主张等合理有依据implies flawless reasoning and solid grounds，如a sound proposal for combatting terrorism打击恐怖主义的合理建议，在2018-06-07 合理valid-telling组中，基础词valid表示真实有效可接受，sound表示不但valid，而且有理有据 ）  又如invalidate a contract/marriage/test result使合同/婚姻/测试结果无效，注意是使无效，不是废除取消


nullify抵消废除: 指完全抵消效力价值，也常指废除，negate否定抵消: 指被互相排斥的二者之一否定(destruct毁灭cancel out取消)，annul废除: 表示通过官方法律行动，使抵消失效废除等，abrogate废除:  更明确表示官方法律行为，还表示目的性，invalidate使无效: 使无效力或变得不可接受，因为存在逻辑道德法律上的错误


记忆方法: 1）首字母NANAI想成NANA和I<==废除      想象你认识《Lonely》中的NANA，共同努力废除了一项不合理的协议或制度。Lonely是一首黑人说唱歌曲，同时加入了R&B和Blues的曲风，歌曲的当中还有女声的伴唱，旋律非常优美

         2）废除的意思是使不再有效存在mean to deprive OF effective or continued existence.    （deprive剥夺means to take something away，如this law will deprive us of our most basic rights这项法律将剥夺我们最基本的权利，如新四20篇they do not realize that they are deprived of the necessities of life他们没有意识到被(大城市)剥夺了生活必需）