( )Little duck is _____the sun go down.
A. watched B. watching C. watches
当你想要询问别人的生日是什么时候时，应该如何问：
A. When do you have breakfast?
B. When is your birthday?
--- _____ they taking a picture?
--- Yes, they are.
A. AmB. IsC. Are
Kate ______ playing chess.
A. am B. is C. are
______ season do you like best?
A. WhichB. WhatC. How
What do you do ______ the weekend?
A. onB. inC. at