Is that a book?

那是一本书吗？

I'm not waiting for anybody.

我不在等任何人。

When you called me, I was eating dinner.

当你打电话给了我时，我正在吃晚饭。

What's matter with you?

你有什么问题吗？

Let's go out to the airport. The plane landed ten minutes ago.

让我们去机场。 飞机在10分钟前降落。

If I want to be healthy,I have to stop smoking cigarettes.

如果我想要健康,我必须停止吸烟。