III.
1. c
2. e
3. a
4. d
5. b
IV.
1. Mr and Mrs Smith are travelling in Ha Noi by plane now
2. Van used to have a motorbike once.
3. My father usually drives to work
4. This part of the city didn't use to have traffic jams
5. I used to go to school on foot when i was young
V.
1. Traffic jam is one of the most common issues in big cities of the world
2. There are many people using road and it is one of the main reasons cause traffic jam
3. We can solve this traffic problem by encouraging people using bicycle rather than car for short trips
4. People should use public transports to reduce the number of private vehicles in the road
5. Moving big companies and factories from the city to the countryside helps reduce traffic jam
