Chuyển sang mệnh đề quan hệ bằng 2 cách sau

huyển sang mệnh đề quan hệ bằng 2 cách (preposition +whom/which+....)
20. The Titanic is the subject of a recent movie. It sank in April 1912
21. The police want to know the hotel. Mr. Foster stayed there two weeks ago.
22. You didn't tell us the reason. We have to cut down our daily expense for that reason.
23. The day was rainy. She left on that day.
24. The reason hasn't been told yet. The president will come here for this reason.
25. Florida attracts many tourists every year. It is known as the Sunshine Stato.
26. She couldn't come to the party. This was a pity.
27. I've sent him two letters. He has received neither of them. 
28. That man is an artist. I don't remember the man's name.
29. The reason isn't valid. You gave it yesterday.
30. We enjoyed the city. We spent our vacation in this city