new oriental supplement volume 3, section11

16. Because natural gas is composed mostly of methane,

a simple hydrocarbon, vehicles powered by natural

gas emit less of certain pollutants than the burning

of gasoline or diesel fuel.

(A) less of certain pollutants than the burning of

   gasoline or diesel fuel

(B) fewer of certain pollutants than burning gaso-

line or diesel fuel do

(C) less of certain pollutants than gasoline or

diesel fuel

(D) fewer of certain pollutants than does burning gasoline or diesel fuel

(E) less of certain pollutants than those burning

gasoline or diesel fuel

answer is e), i thought d) is much better than e)..