He has no small reputation as a scientist．他是名气很大的科学家。

No way is impossible to courage．勇士面前无险路。

Nothing is unnecessary．没有什么是不必要的。

We cannot succeed without your help．

没有你们的帮助，我们就不能成功。

It is not uncommon for students to have friendly relationship with their teachers．

学生与老师建立友好关系并不罕见。

It is conflict and not unquestioning agreement that keeps freedom alive．

使自由保持活力的是冲突而不是绝对的一致。