Is there a precedent for what you want me to do?

你要我做的事有先例吗？

The judgment set a new precedent.

那次判决树立了一个新的判例。

In civil law law department country,legal precedent has no binding force but has convincible force in practice.

在民法法系国家,判例并没有约束力,但在,它具有说服力。

We may as well assert that because a child has thriven upon milk, that it is never to have meat, or that the first twenty years of our lives is to become a precedent for the next twenty.

你还不如说，因为一个孩子是吃奶长大的，所以他永远不该吃肉，或者说，我们一生的开头二十年应该成为第二个二十年的先例。