Why don't you take the day off?

Why don't we go to the mountains this weekend?

Why did you try to run away?

Why do you accuse my son?

Why do you want to study abroad?

Why do you want to buy this book?

It is obvious why you have a stomach-ache.

There is no reason why you shouldn't do such a thing.

Why didn't modern technology develop in China?

I don't know why the meeting was postponed.