deny: implies a firm refusal to accept as true, to grant or concede, or to acknowledge the existence or claim of: tried to ~ the charges.


gainsay: implies an opposing, usually by disputing, of the truth of what another has said: no one dares ~ the truth of what I've said.


contradict: implies an open or flat denial of the truth of an assertion, and usually suggests the reverse is true: her report ~ every point of his statement to the press.


traverse: chiefly a legal term, implies a formal denial (as of an allegation or the justice of an indictment): ~ the accusation of fraud in his opening remarks.      (indict正式指控)


impugn: implies a forceful, direct attacking, disputing or contradicting of something or someone, often by prolonged argument: dared to ~ his motives.  注意是impugn不是impune。


contravene: implies not so much an intentional opposition as some inherent incompatibility: laws against whaling that ~ Eskimo tradition.


deny否认: 坚定拒绝接受给予让步承认(accept,grant,concede,acknowledge)，gainsay也是否认: 指对真实性的否认争议，contradict抵触矛盾: 公开直截的否认是事实，用于截然相反(the reverse is true)的矛盾观点：如果命题是真/假，则反命题一定是假/真， traverse: 正式、法律用语的否认(如指控诉讼等)，impune质疑争议: 长篇有力直接的攻击质疑， contravene违反: 由于内在不兼容，而非故意反对。


记忆方法：1）DGC TIC首字母DGC想成共产党，TIC想象成Taiwan Is Country: 共产党否认台湾是国家。


          2）否认的意思是拒绝承认真实有效mean to refuse to accept as true or valid.