1. You must do your homework before going to school.

2. We must be present at the class discussion on Saturday.

3. Tokyo is larger than Ha Noi and Bangkok.

4. We mustn's throw rubbish.

5. How many apples would she like?

6. It is very easy to learn how to use a computer.

7. He is a careful driver

8. Students at our school do a lot of outdoor activities.

9. I have difficulty in finding a better solution to that problem.

10. Lan has 2 younger sisters.

1 It is essential that you do your homework before going to school.

 You must do your homework before going to school.

2. It is necessary for us to be present at the class discussion on Saturday.

 We must be present at the class discussionon saturday.

3. Hanoi is large, Bangkok is large and Tokyo is the largest.

 Tokyo is the largest of the tree cities

4. It is wrong of us to throw rubbish..

 We mustn’t throw rubbish

5. How many apples does she want?

 How many apples would she like?

6.Learning how to use a computer is very easy

 It is easy to learn how to use a computer

7. He drives very carefully.

 He is a careful driver

8. Students at our school take part in a lot of outdoor activities

 Students at our school do a lot of outdoor activities

9.I find it difficult to find a better solution to that problem.

 I have a difficulty in finding a better solution to that problem

10. Lan is the oldest of the three sisters

 Lan has two younger sisters