1.-There is less pollution in the city than in the countryside
-There is more pollution in the countryside than in the city
-There isn't as much pollution in the countryside as in the city
2.-Class 7a3 has fewer students than class 7a2
- Class 7a2 has more students than class 7a3
-Class 7a3 doesn't have as many students as class 7a2
3.-Children in cities suffer less malnutrition than those in slums
- Children in cities don't suffer as much malnutrition as those in slums
-Children in slums suffer more malnutrition than those in cities