解释

　　这个词字面上解释“Without which, not.”。也就是说“Without(A),(X)won’t be possible.”没有A的话X是不可能的，自然就可以理解成A是X的前提或者A对于X至关重要。

　　不同来源的例句

　　A solid customer base is the sine qua non to success.

　　坚实的客户基础对于成功很重要。

　　A good agent is a sine qua non for an actor’s career.

　　一个好的经纪人对于演员的职业生涯至关重要。

　　His support was really the sine qua non for her candidacy.

　　他的支持对于她的候选人资格真的十分重要。

　　From: Merriam-Webster’s Vocabulary Builder

　　That is depressing for those who seek Martians, even bacterial ones, for most biologists agree that liquid water is a sine qua non of life.

　　对于那些寻找来自火星的哪怕是细菌生物的人来说，那是令人沮丧的。因为大部分生物学家都会同意水是生命之源。

　　Permits became sine qua non, but in poorer countries the environment ministries that were expected to issue them did not always exist.

　　许可证变得尤为关键，但是在贫穷的国家，本应该颁发这些证件的环保部门并不存在。

　　From: The Economist

　　There is, though, one thing these two founders are missing, and it is almost the sine qua non of the fabled Silicon Valley startup.

　　两个创始人忽视了一个东西，而它对于传说中的硅谷的创业公司非常重要。

　　From: Newsweek

　　The control of inflation is a sine qua non for economic stability.

　　控制通货膨胀是经济稳定的前提。

　　From: Longman Dictionary