1. New York has more billionaires than Tokyo.

→Tokyo has fewer billionaires than New York

2. A group of foreigners visited the slums last week, didn’t they? 

→Did a group of foreigners visit the slums last week?

3. The countryside doesn’t suffer as much pollution as the city. 

→The countryside is less suffer pulluation than the city

4. Does overpopulation cause a lot of social problems in this area? (CAUSES) 

→overpopulation causes a lot of social problems in this area, doesn't it?

5. Jakarta doesn’t have as many skyscrapers as Shanghai. (MORE)

→Shanghai has more skyscrapers than Jakartar

6. Let’s go to the school cafeteria. (ABOUT)

→How about going to the school cafeteria?