1. What problems have become one of the most urgent problems of modern society?
2. What do more and more people suffer from?
3. The reasons for such environmental problems are numerous, aren't they?
4. Is increasing number of cars in the streets one of the main problem?
5. How many trees were cut down?
6. Who all these problems mainly arise due to?
7. Are there many ways to suspend these problems?
8. Must we start caring about the planet we live in?
9. What can we save if we start recycling paper and cardboard?
10. In what case can we have less air pollution?
11. Who can also help to prevent some problems?
12. We might have to face many global disasters, might not we?
When I came home, my mother was having breakfast.
She was doing her homework at 4 o'clock yesterday while I was at school.
My aunt was writing a letter to me at 5 o'clock yesterday while I was on my way to my grandmother.
My uncle called me a few times while I was decorating a Christmas tree.
My brother and sister were playing basketball, while I was at canteen.