3/ Mr Smith used to live on a farm in the coutryside.

4/ The teacher asked her students not to forget to say thank you to your moms. 

5/ My mother said that I shouldn't stay up surfing the internet too late.

6/ My school isn't bigger than Tuan's school.

7/ Mr Lam has worked in that hospital for two months.

8/ Nam is intelligent enough to pass the exam. 

3.Mr.Smith used to liven on a farm in the countryside.

4.The teacher asked her students not to forget to say thank you to their mom.

5.My mother said to me that I should not stay up surfing the internet too late.

6. My school isn't as big as Tuan's one.

7.Mr.Lam has worked in that hospital for two months.

8.Nam is intelligent enough to pass the exam.