1. The environment in the city is much polluted than that in the countryside.
-> more
2. In the countryside, houses are often little furnished and bigger than those in the city.
-> less
3. The communication system in the countryside become more modern in the last ten years because electricity is available in more places.
-> place
4. I prefer live in the countryside than in the city, people are normally healthier and fitter.
-> living
5.50 years ago, farmers depended more heavy on the weather than at present.
-> heavily
6. I'm not sure about what we should to do
-> do
7. Are we going to must work overtime again this week?
-> have to
8. We have many things to do this week, so I don't know if I can't go to English class.
-> couldn't
9. I have to thought about the problem for a while, but I finally figured it out.
-> think
10. You should quiet in class; otherwise, your classmates can't concentrate.
-> be quiet
