英语中which引导什么从句

There are two points which I wanted to make.

我想要指出的有两点。

We are still friends, though, which is good.

不过我们仍然是朋友，这令人感到欣慰。

Which part of Japan do you come from?

你是日本哪个地区的人？

There is some noise in the data which needs to be reduced.

资料里有一些需要删除的不适用信息。

Which is the largest city in the world?

世界上最大的城市是哪个？