30. The teacher, ______ it clear to us that she would punish John if he was late for school again, left the classroom angrily.

　 A. having made　　 B. who has made　　 C. made　　 D. making

29.While I was chatting with one of my friends on the Internet, ______ occurred to me ______ I needed to download some information about my research.

　 A. what; that　　　 　B. what; which　

C. it; which 　　　　D.it; that

28. I love to climb to the top of the mountain and stay there for some time. It ______ good to breathe in the clean and fresh air there.

　 A. does　　 B. feels　 　C. gets　　 D. makes

27. It was owing to luck ______ judgement ______ the driver succeeded in avoiding an accident.

　 A. better than; when　　 B. rather than; that　　

C. other than; when　　 D. more than; which

26. Colds are very ______ in that area every spring and early summer.

　 A. ordinary　　 B. common　　 C. popular　　 D. general