37. The reason ______ he didn’t come was his mother’s illness.

A. which　　　 B. why　　　　　 C. whether　　　 D. because

36. The freezing point is the temperature ______ water changes into ice.

A. at which　　 B. on that　　　　 C. in which　　 D. of what

35. There is nothing ______ I want to say.

A. which　　　 B. what　　　　　 C. whatever　　 D. that

34. Don’t talk about such thing of ______ you are not sure.

A. which　　　 B. what　　　　　 C. as　　　　　 D. those

33. Susan will not arrive at the airport on time ________ she hurries up.

A. once　　 B. if　　 C. when　　 D. unless

32. Can you tell me why ______ yesterday?

A. are you late　　 B. you were late　　 C. were you late　　 D. you are late

31. ----Excuse me, could you tell me ______ later on?

　 ----Wait a minute. It is coming in ten minutes.

A. if the next train arrives　　　 B. if the next train will arrive

C. when the next train arrives　 D. when will the next train arrive

30. Sam tried his best in the race, but he didn’t run so ______ as Tom.

A. fast　　 B. faster　　 C. quickly　　 D. slower

29. ----You MP3 is so nice. How much is it?

　 ----It ______ me $300.

A. bought　　 B. spent　　 C. cost　　 D. paid

28. She’s milked a cow before, ______ she?

A. doesn’t　　 B. hasn’t　　 C. wasn’t　　 D. isn’t