Đáp án: 

part 5:

1. Lan has studied english 5 years ago.

2. Although the sun was shining, it's wasn't very warm.

3. Nam used to live with his parents.

4. You musn't talk with food in your mouth.

5. I prefer traditonal dances better than modern ones.

part 6:

1. tipping isn't custom in VN, so you haven't to tip if you don't want.

2. In Brazil, standar tip in restaunt is 10 percents.

3. The Xoe dance is peformed boys and girls in the hamlets.

4. We haven't to take shoes when we go inside the pagoda.

5. Nowadays, teenagers rely on technology more than in the past.

Part 5:

1. Lan has been studying English for 5 years.

2. Although the sun was shinning, it wasn't very warm.

3. Nam used to live with his parents.

4. You shouldn't talk with food.

5. I prefer traditional dances to modern ones.

Part 6:

1. Tipping is not a custom in Vietnam , so you don't have to tip if you don't want.

2. In Brazil, the standard tip in restaurants is 10 percent.

3. The xoe dance is performed by the boys and girls in the hamlets.

4. We have to take off our shoes when we go inside a pagoda.

5. Nowadays teenagers rely on technology more than in the past.