prerequisite       
noun [ C ]  formal uk/ˌpriːˈrek.wɪ.zɪt/ us/ˌpriːˈrek.wə.zɪt/
 先决条件,前提,必备条件
something that must exist or happen before something else can exist or happen
  Passing a written test is a prerequisite for taking the advanced course. 通过笔试是学习高级课程的前提。 
 Public support is a prerequisite for/to the success of this project. 公众支持是这一计划取得成功的必备条件。 
 They had to agree to certain conditions as a prerequisite of being lent the money. 他们不得不同意一些条件才能借到钱。 
 Synonym: requirement