1. In my family, all of children are obliged to get up before 6 a.m and do exercise.

2. It's necessary for students to book in advance to use the computer at the school library.

3. In most of the temples and pagodas in Vietnam, you are allowed to take off your shoes when going outside the main worship areas.

4. To visit Ho Chi Minh Mausoleum, people are obliged to hand in their idenity cards.

5. n Vietnam, people can't drive on the left of the road.

Giải thích:

1. To be obliged to do something: một người có nghĩa vụ làm gì đó

2. It is necessary (+ for somebody) + to do something
It is necessary + that + S + V

3. BE ALLOWED + TO VERB

4. To be obliged to do something: một người có nghĩa vụ làm gì đó

5. S + Can’t (Can not) + Vinf…