He has_____ work to do, so he can’t go with you.
Knowing how to _______ a map can help you when you are travelling in a strange place.
Now the air in our city is _______ than it used to be. Something must be done to stop it.
—The books are so nice, which one can I take?—Oh, you can take _______ of them. I’ll keep none.
I wanted to explain, but he didn’t give me any _______.
—Who is playing the piano in the classroom?—_______ must be Susan. She plays the piano after school every day.