EX3
1. were ____ went
2. didn't go ____ stayed ____ did
3. isn't working
4. Did you watch
5. haven't taken
EX4
1. I have just come back from Nha Trang in a vacation.
2. Quoc Tu Giam was the first university in Viet Nam.
3. There are six continents in the world.
4. It is the most famous tower in England.
5. The old buiding is more than 100 years, but it looks new.
EX5
1. carefully
2. beautiful
3. nationality
4. tallest
5. leaves
6. sunny
7. singer
8. teeth
9. Chinese
10. noisy
EX6
1, B
2, A
3, D
4, A
5, C
