=>
I/
1. C
2. A
3. B
4. D
II/
1. How far is it from your house to your school?
2. It is not very far to go to the railway station.
3. We must always obey the traffic rules for our safety.
4. There is a children crossing sign near our school, so you must cross the road there.
III/
1. Now there are more cars on the road than before.
2. My brother used to be a professor at Ha Noi University some years ago, but now he has aajob as an engineer at a big company.
3. Linh used to walk to school some years ago but now she cycles there.
4. My faher used to swim in the pool near his house when he was a boy.
5. There used to be many green trees in front of my house but now it is a big car park.