Have you returned the book to the library ____?         --- Yes, I have ____ returned it.

—Do you like ball games? —Yes. They are very fun.

— Dave is always making the same mistake. It worries me a lot. — Take it easy.           , he is only a child.

I don’t like those big cities which have got ____ people and ____ traffic.

 All the _________ things need air and water. Without air or water, nothing can stay _______.