17．(上海市嘉定黄浦2010年4月高考模拟文科)已知无穷等比数列的前项和，且是常数，则此无穷等比数列各项的和是……………………………………………………………………………………(　 D　 )

A．．　　 　B．．　　　 C．．　　　 D．．

40. -----I’m thinking of the test tomorrow, I’m afraid I can’t pass this time.

-----_________! I’m sure you’ll make it.

A. Go head　 B. Good luck　 C. No problem　 D. Cheer up

39. The Great Wall is ______ tourists attraction that millions of people pour in every year.

A. so a well known　　　 B. such a well known

C. a so well known　　　 D. such well known a

38. It ___ have been Tom that parked the car here , as he is the only one with a car.

A may　　 B can　　 C must　　 D should