null 核心词议：
adj. <术>零值的;等于零的;（协议） 无法律效力;失效的;
null 基本解释
adj. <术>零值的；等于零的；（协议） 无法律效力；失效的
速记方法知识扩展
习语积累
习语 adj. null and void (law 律) (of an election, agreement, etc. 选举、协议等) 无法律效力的；无效的 having no legal force; not valid The contract was declared null and void. 合同被宣布无效。
词根词缀
词根 null= none 没有, 无 annul v. 取消 an 加强 + nul〔= null〕没有，无 → 变没有 → 取消 null adj. 无效的；等于零的 nullification n. 无效；废弃 null 没有，无 + ification 形成… → 无效；废弃 nullify v. 取消；废除 null 没有，无 + ify 使… → 取消；废除
null 记忆方法
中文词源：
null
精选例句
1、 The marriage was declared null and void.
婚姻已宣告无效了。
2、 Their actions rendered the contract null and void.
他们的行为使合同无效。
常见考点例句：
- What would be the null hypothesis , the kind of conjecture that you 'd make assuming nothing further .
- 什么是无效假设？那种你以为没什么可深究的臆测。
- So henry called a council with the pope where he claimed that catherine had boned his older ( subsequently deceased ) brother arthur before she married henry , and thus their current marriage was null and void .
- 亨利召集有主教参加的议会，声称凯瑟琳在嫁给他之前已经和他的兄长阿瑟（已亡故）睡过了，这样他们的婚姻就无效了。
- But gay rights advocates say it is important to gather backers for statements , resolutions and other documents such as the one that will be presented tuesday by the united states , even when their legal effect is null .
- 但是同性恋权利倡导者表示为这些声明、决议和其他文件诸如周二将由美国提出的那份声明取得更多的支持者很重要，尽管它们的法律效力是无效的。
- Just ahead of a deadline for companies to submit their plans for compliance , the movement for democratic change , the former opposition party that is locked in an unhappy national unity government with mr mugabe 's lot , said that the cabinet had pronounced the regulations " null and void " .
- 就在提出要求公司提供股权变更方案的期限之前，民主变革运动---以极不情愿的姿态与穆加贝先生组成民族统一政府的前反对党---声称内阁已经宣布该法案在法律上的无效性。