1.There are more than three _____ different trees in the primeval forests.
A.thousands of B.thousand of C.thousands D.thousand
2.The students are sorry to hear that the famous singer ____ for half an hour.
A.has left B.has gone C.has gone away D.has been away
3.Not only his parents but also his brother _____ to China.
A.have been B.have gone C.has been D.has gone
4.This is _____ bedroom.The twin sisters like it very much.
A.Anne and Jane B.Anne's and Jane's C.Anne's and Jane D.Anne and Jane's
5.In summer not many children like ____ football in the playground because it is
very hot.
A.to play B.playing C.is playing D.plays
6.A：Is chemistry more difficult than physics?
B：No,chemistry isn't as _____as physics.
A.easy B.difficult C.easier D.more difficult