3. I haven't seen Peter for five months.
4. It has rained for two hours. 
5. Although the film was very boring, he still watched it.
6. Nam is the most hard-working student in his class.
7. If we use less cars and motorbikes, we won't make the air dirty.

1. ​I have never talked to a foreigner before
2. Ho Chi Minh city is the most crowded city in Viet Nam
3. I haven't seen peter for five months
4. It has rained for two hours

5. Although the film was very boring, he still watched it.
6. Nam is the most hard-working student in his class.
7. If we use less cars and motorbikes, we won't make the air dirty.

1. I have never talked to a foreigner before. 
2. Ho Chi Minh city is the most crowded city in Viet Nam.
3. I haven't seen Peter for five months.
4. It has rained for two hours. 
5. Although the film was very boring, he still watched it.
6. Nam is the most hard-working student in his class.
7. If we use less cars and motorbikes, we won't make the air dirty.