1. is less pollution in the city than in the

is more pollution in the countryside than in the

isn't as much pollution in the countryside as in the 

2. has fewer students than

has more students than

doesn't have as many students as

3. suffer less malnutrition than those in slums

don't suffer as much malnutrition as those in slums

suffer more malnutrition than those in cities

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