We will play football if it ________ this Saturday.
doesn't snow
won't snow
isn't snowing
didn't snow
There ____ a book and a pen on the desk.
The cup is on _____ desk.
Are they doing____ homework?
What are you ____?
--____ does Mary ___? ---The USA. A. When; come from B. Where; from C. How; go D. Where; come from