E.

I.

66. Our summer vacation lasted for two month last year.

67. I spent about  two hours doing my homework yesterday

68. They used to see nobody in the room

69. My sister wasn't able to swim last year

70. You won't have to/need to go to the meeting next week

71. American students have more vacations than Vietnamese ones

72. How much heavy was your father last year?

73.How beautiful the Christmas tree is

74.The colourful little fish was the most beautiful fish in the aquarium 

75. Why didn't you go to class last Monday?

76.How long did you flew from Hanoi to Jakarta?

77.It will be impossible to come one Saturday

78. The rooms in that hotel are more comfortable than these in that hotel