II)
1)of 2) at 3)about 4)for 5)of 6)after
III)
1)I was absent from class yesterday because I was sick
2)Minh is going to see the dentist because He has a toothache
3)She has healthy teeth because She brushes her teeth after meals
4)Children have toothache because They often eat a lot of candy
5)He was happy because his decaying ....
6) Because We jog every morning, It's good for our health
IV)
1)wasn't
2)bad
3)you
4)yesterday
5)what
6)were
7)how
8)filled
I)
1) C 2)A 3)C 4)A 5)C 6)A 7)B 8)A