21. We'll have a trip to the Great Wall next Sunday. Can you help me o                 it?

22. She felt u                 at the disappointing result.

23. I also a                 you to take a basic multivitamin every day.

24. Sometimes it's hard to s                 the problem by myself.

25. He always tells lies, and I don't t                 him at all.

26. People travel to meet new friends, to try new food, to e                 life in other parts of the world.

27. I was late for class today. The teacher was a                 with me.

28. We call the persons who are between 13 and 19 t                .

29. I prefer t                 by train to staying at home.

30. It's c                 of him to make such a mistake.

31. Who will o                 the meeting? We'll have many things to do.

32. He didn't pass the exam, so he was u                .

33. You'd better a                 him to wear warm clothes in cold days.

34. You can ask your father to help you s                 this problem.

35. My mother often tells me not to t                 the strangers.

36. He is a good teacher with much e                .

37. Sam played computer games a lot. His mother was a                 with him.

38. You can't drive. You're only 15. You're just a t                .

39. I want to t                 to New York when I am free.

40. Tom is very careful, but his brother is c                .

41. Who do you                 (信任) when you are in trouble?

42. A social worker always listens to people's problems and helps them                 (解决) their problems.

43. He was so      &nb