—How many students are there in the classroom?
—_____ I don’t know where they have gone.
A.No one. B.None. C.Nobody. D.Nothing.
The rubbish _____ is produced every day is becoming a serious problem in cities around the world.
A. what B.that C.who D.whose
More and more trees were cut down. _____, many animals are dying out.
A.In the end B.So that C.As a result D.At last
We should often keep _____ touch with each other, because we are good friends.
A.on B.to C.in D.up
Everyone knows that a desk is made wood and paper is made wood, too.
A. of , of B. of , from C. from , from D from,of
—Do you know _____?
—Sorry, I don’t know.
A.what’s the population of Japan
B.what the population of France is
C.how much of the population of Japan is
D.how many is the population of France
