1. Doing math exercises is difficult
=> It isn't
2. It isn't necessary for you to go to school so early
=> You don't
3. Playing with matches is very dangerous
=> It
4. It is helpful to learn English
=> Learning
5. Must he leave now?
=> Does he
6. Noone helps her sweep the floor
=> She
7. Nobody helped us tidy our rooms
=> We
8. Nga does the housework without any help
=> Nga
9. The lighting fixture is above the table
=> The table
10. You shouldn't stay up late
=> You ought
1. Doing math exercises is difficult
=> It isn't easy to do math exercises
2. It isn't necessary for you to go to school so early
=> You don't need to go to school so early
3. Playing with matches is very dangerous
=> It is very dangerous to play with matches
4. It is helpful to learn English
=> Learning English is helpful
5. Must he leave now?
=> Does he need to leave now?
6. Noone helps her sweep the floor
=> She doesn't need someone sweep the floor
7. Nobody helped us tidy our rooms
=> We don't need somebody tidy our rooms
8. Nga does the housework without any help
=> Nga doesn't need someone do the housework
9. The lighting fixture is above the table
=> The table is under the lighting fixture
10. You shouldn't stay up late
=> You ought not to stay up late
1.It isn't easy to do math exercises
2. you don't need to go to school so early
3. it is very dangerous to play with matches
4.Learning English is helpful
5.Does he need to leave now?
6. She sweeps the floor by herself
7. We tidy our rooms by ourselves
8. Nga does the housework by herself
9. The table is under the lighting fixture
10. You ought not to stay up late
Bn tham khaor nha
Hok tot~