This is the computer (that/which) he bought for his son yesterday.
这是他昨天为儿子买的电脑。
I will show you to the supermarket where you can find everything you want.
我带你去一家超市，在那里你能找到你想要的一切东西。
He is English, which I know from his accent.
他是英国人，那是我通过他的口音知道的。
This is our headmaster, who I think has something important to tell you.
这是我们的校长，我认为他有一些重要的事情要告诉你。
