21. I’m not looking at ____

　 A. sun　　　　 B. sky　　　　　 C. the sun　　　　　 D. some sky

20. ____ birds can fly very high in ____ sky.

　 A. The, the　　 B. The, a　　　　 C. An, the　　　 D. A, the

19. You will find ____ girl in black. She is ____ teacher.

　 A. a, the　　　 B. the, a　　　　 C. a, a　　　　　 D. the, the

18. Who are those boys? One is my brother and ____.

　 A. the big boy is Mike　　　　　　 B. a big is Mike

　 C. the big boy is a Peter　　　　　　 D. a big boy is a Peter

17. They failed six times, but they have decided to try____.

　 A. seven times　 B. the seven time　 C. the seventh time　 D. seventh time

16. My uncle told me he was going to visit ____.

　 A. the United State　 B. The United States　 C. United States　 D. United State

15. I’ve thrown my old shoes away. I’ll have to buy ____.

　 A. a new pair　　 B. a new one　　 C. some new　　 D. some new pair

14. I’ll have to buy ____ trousers.

　 A. a　　　　　　 B. two　　　　 C. a pair of　　　 D. pair

13. What do you usually do after ____?

　 A. the class　　　 B. class　　　 C. the classes　　 D. a class

12. Hainan is ____ island, isn’t it?

　 A. the　　　　　　 B. one　　　　　 C. a　　　　　　 D. an