21. --- What is your favourite subject?

--- It's s                .

22. Our g                 teacher is Mr. Lu. He tells us some interesting places(地方).

23. Now teenagers are not interested in h                . They know less about the old days.

24. M                 is the second day of a week.

25. It's F                 today.

26. We don't go to school on S                 or Sunday.

27. The third day of the week is T                .

28. W                 is the fourth day of a week.

29. It's a u                 book. You can learn a lot from it.

30. T                 is the fifth day of the week.

31. There are four s                 labs in the building.

32. We can learn about famous mountains and rivers in g                 class.

33. China is a country with a very long h                .

34. Tuesday comes after M                .

35. We go to school from Monday to F                .

36. In western countries, people think Sunday is the beginning of a week, and S                 is the last day in a week.

37. The third day of the week, T                 is between Monday and Wednesday.

38. The day before Thursday is W                .

39. The Internet is becoming very u                 for language learning.

40. The day after Wednesday is T                .

41. If you learn even a little English, you will find it                 (有用的).

42. It's hard                 (完成) the work in such a short time.

43. John looks                 (酷的) in the new windbreaker.

44. I like to play ping-pong on    &nbs