=>

33. They had been on board before he arrived at the airport

→ As soon as he arrived at the airport, they had been on board.

34. How long have you possessed that Chanel bag?

→ When didyou start possessing that Channel bag?

35. " Why do I have to conduct this research ?" she asked me

→ She asked me why she had to conduct that research.

36. He needs to talk to the psychologist about his current situation

→ It is necessary for him to talk to the psychologist about his current situation.

37. It is very useful to know English.

38. It has snowed since 5 o'clock.

39. Hung isn’t as tall as Nam.

40. What time did you go to bed yesterday?

33.as soon as he arrived at the airport, they had been on board.

34.when did you start possessing that Channel bag?

35.she asked me why she had to conduct that research

36.it is necessary for him to talk to the psychologist about his current situation.

37.it is very useful to know English

38. it has snowed since 5 o'clock

39. Hung isn’t as tall as Nam

40.what time did you go to bed yesterday?