164. 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 gasoline 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 给的答案是E,pollutants是可数,用less of 修饰可以马?