.Could you please pass me two ________?
A.pieces paper B.piece paper
C.pieces of paper D.pieces of papers
Everyone should play a part_____the earth.
A.to save B.saved
C.for saving D.in saving
Please check your paper to ________ there are no mistakes.
A.think of B.try out C.find out D.make sure
Liu Xi's father kept on____although he was tired.
A.to sleep B.sleeping C.to work D.working
World Cup host Brazil would like to help China________China's soccer.
A.improve B.send C.question D.discuss
Mrs. Green promised____all she can to help us.
A.knowing B.to know C.doing D.to do