4.We should prevent pollution________happily.
A.from living
B.living
C.to living
D.to live
5.Jane came very close_______a gold medal for Britain in the Olympics.
A.to win
B.winning
C.to winning
D.to be won
6.There is _______what the weather will be like
A.not knowing
B.no knowing
C.not know
D.no known