61. I had not to work yesterday because it was my day off.
B. "had not" → The correct form is "did not have to".
The correct sentence is: I did not have to work yesterday because it was my day off.
62. You must try to make these children clean their tooth.
C. "their tooth" → The correct form is "their teeth" (plural of tooth).
The correct sentence is: You must try to make these children clean their teeth.
63. There is many furniture made of wood in the sitting room.
B. "There is many" → The correct form is "There is much" or "There are many" (for plural countable nouns).
The correct sentence is: There is much furniture made of wood in the sitting room.
64. Eric now drives his bike to school instead of traveling by bus.
C. "now drives" → The sentence would sound more natural with "nowadays drives" or "drives now".
The correct sentence is: Eric drives his bike to school now instead of traveling by bus.
65. Life is more comfortably now and people enjoy watching TV at their own home.
B. "more comfortably" → The correct form is "more comfortable" (adjective, not adverb).
The correct sentence is: Life is more comfortable now and people enjoy watching TV at their own home.
66. Look at these two beautiful vases. Which one do you like best?
No mistake here. The sentence is correct.
67. Nowadays people are living longer so they are more elderly people.
C. "more elderly people" → The correct phrase is "older people".
The correct sentence is: Nowadays people are living longer so they are older people.
68. What do you usually do at recess? Do you play some games?
C. "some games" → The correct form would be "any games" (in a question).
The correct sentence is: What do you usually do at recess? Do you play any games?
69. I am terrible sorry. I didn't mean to break your windows.
A. "am terrible sorry" → The correct form is "am terribly sorry" (adverb + adjective).
The correct sentence is: I am terribly sorry. I didn't mean to break your windows.
70. On the back of the school yard there is a big apple tree.
A. "On the back of the school yard" → The correct phrase is "At the back of the school yard".
The correct sentence is: At the back of the school yard there is a big apple tree.