1. Sydney is the largest city in Australia.
2. I saw a very interesting film yesterday.
3. By the time I started primary school, I had learned how to ride a bicycle.
4. We've decided to stay in Hanoi for ten days.
5. What about giving a presentation about water and air pollution ?
II.
1. A lot of trees are going to be planted in the park.
2. If I had enough money, I could buy this car.
3. Because his room is untidy, his mother isn't happy.
4. I prefer listening to music to watching TV.
5. English has been learn for four years.
III.
1. English is spoken all over the world.
2 Nhi enjoyed chatting on the phone with her friends.
3. Noise pollution in big cities lead to hearing problems.
4. If you are a president in your country, what will you do to protect the environment ?
5. A lof of energy sources can be saved by recycling.
