1. You must do your homework before going to school
2. HCM city is the most crowded place I have ever seen
3. Why don't we talk to our teacher about the problem of learning enlish?
4. I haven't played badminton since my son was born
5. Helen is good at speaking english
6. It is easy to learn how to use a computer
7. John is the most hard-working student in our class
8. Walking on foot with his friends, Nam goes to school