52.(　　 ) The lights must 　　　　　before you leave the classroom.

A. turn on　　　　 B. turn off

C. be turning on　　　　　 D. be turned off

51. The Changjiang River is　　　 　　than any other river in China.

A. shorter　　　　 B. longer　　　 C. shortest　　　　 D. longest

50.(　　 ) Which of the following weather signs means "windy"?

A.　　　　 B.　　　　 C.　　　　 D.

49.(　　 ) -　　　 　your sister　　　 　in Greener Chi­na for a long time?

-Yes.　 She joined it five years ago.

A. Has:　 been　　　　 B. Have:　 been C. Has : joined　　　　 D,　 Have : joined

48.(　　 ) -I think English is more useful than Chinese.

-I don't　　　 　you. They are both useful.

A. get on with　　　　 B. catch up with C. talk with　　　 D. agree with

47.(　　 )　 -　　　 　do you write to your pen friend?

-Twice a month.

A. How often　　　　 B. How soon

C. How long　　　　　 D. How many times

46.(　　 )-When are you going to Kunming for your holidays?

-I haven't decided.　　　 　　this Sunday　　　 　next Sunday is OK.

A. Both:　 and　　　　　 B. Either:　 or

C. Neither: nor　　　　　 D. Not only:　 but also

45.(　　 ) Why not swim in this river?

-Oh,　 no.　 Mum told me 　　　　　here. It's dangerous.

A. will swim　　　　 B. to swim　　　 C. to not swim　　　　　 D. not to swim

44.(　　 ) -Can you stay here for dinner?

-Sorry, I　　　 　.　 I have something impor­tant to do.

A. don't　　 B. didn't　　 C. needn't　 D. can't

43.(　　 ) -How many people will come to Beijing for the Olympic Games in 2008?

--It's hard to say.　　　 　people, I think,

A. Million of　　　　 　B. Millions of

C. Two millions of　　　　 D. Two million of