27. I'm the person whose flat you stayed.

28. This is a story of a group boys whose plane crashed on an uninhabited island.

29. This is Mrs. Jones, whose son won the championship last year.

30. I know the woman whose son you bought the car from.

31. The roads were crowded with refugees, many of whom were wounded.

32. The lorry crashed into a bus-load of schoolchildren, six of whom were slightly injured.

33. In prison they fed us on dry bread, most of which was mouldy.

34. I saw several houses, most of which were quite unsuitable.

35. He introduced me to his students, most of whom were from abroad.

36. He expected me to pay 2$ for 12 eggs, four of which were broken.

37. They gave me four very bad tyres, one of which burst before I had driven four miles.

38. The car crashed into a queue of people, four of whom were killed.

39. We need a room where we can study.

40. He invited her to eat out on a day, on which it rained heavily.

41. The day on which she arrived was sunny.

42. September 2nd 1945 was the date on which President Ho Chi Minh declared the Independence of Vietnam 
43. I am going to visit the town in which I was born and grew up
44. Hanoi is the city in which I was born.

27. I'm the person  whose flat you stayed.

28. This is a story of a group boys whose plane crashed on an uninhabited island.

29. This is Mrs. Jones, whose son won the championship last year.

30. I know the woman whose son you bought the car from.

31. The roads were crowded with refugees, many of which were wounded.

32. The lorry crashed into a bus-load of schoolchildren, six of whom were slightly injured.

33. In prison they fed us on dry bread, most of which was mouldy.

34. I saw several houses, most of which were quite unsuitable.

35. He introduced me to his students, most of whom were from abroad.

36. He expected me to pay 2$ for 12 eggs, four of which were broken.

37. They gave me four very bad tyres, one of which burst before I had driven four miles.

38. The car crashed into a queue of people, four of whom were killed.

39. We need a room in which we can study.

40. He invited her to eat out on a day, on which it rained heavily.

41. The day on which she arrived was sunny.

42. September 2nd 1945 was the date on which president Ho Chi Minh declared the Independence of Vietnam 
43. I am going to visit the town in which I was born and grew up
44. Hanoi is the city in which I was born