3. of ,　 which　　　　　　　　 4. not/never give up ,until, convincing

1. show great interest in　　　　 2. get frightened,　 flying over

1---5.　 ABCCD　 6---10. DCBBC　 11---15.　 ADDBA

8.　　　 Liu Xiang didn’t let Chinese people down with a c_______________ win in the men’s 110m.

7.　　　 In the past three years, scientists have done a lot of 　r____________ on the cause of SARS.

6.　　　 There is no p________________　 that they can finish the work ahead of the time because of the bad weather.,

5.　　　 It is said the old lady is the only w_____________　 to this car accident.