We need it to complete the clause in the sentence.

我们需要它来完成句子中的子句。

We discussed relative clauses in an earlier Everyday Grammar story.

我们在之前的每日语法已讨论了关系从句。

You can also reduce the clause in a sentence to a phrase.

你也可以把句子中的从句变成一个短语。

Without it, we're still going to understand the clause in the sentence.

没有它的话，我们还可以理解句子里面的从句。

I know, but Sheldon had this clause in the Relationship Agreement forbidding cosmetic surgery unless it's to look like a Klingon.

我知道，但谢尔顿在《恋爱协议》里明文禁止做美容手术，除非做出来效果像克林贡人。

To use relative clauses in this way, you need to do two things.

要以这种方式使用关系从句， 您需要做两件事。

Because sometimes you want to place your clauses in a relationship that makes sense.

因为有时你想把你的子句放在一个有意义的关系中。