Peter looked __________. He was looking __________ at his friends.
A.happy; happily B.happy; happy
C.happily; happy D.happily; happily
The government warned the factories _____the water again.
A.pollute B.to pollute
C.not pollute D.not to pollute
The train __________ for Beijing soon. The passengers who are still on the platform should get on the train at once.
A.leaves B.is leaving C.left D.leaving
Trees make our streets__________ and__________.
A.more beautiful; less noise B.more beautifully; less noisy
C.less beautiful; more noise D.more beautiful; less noisy
Are these tigers __________ great danger?
A.of B.in C.for D.at
I know that trees can communicate __________ one another.
A.with B.on C.by D.in
