128. 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 of gasoline or diesel fuel do C. less of certain pollutants than gasoline or diesel fuel D. fewer of certain pollutants than does burning of gasoline or diesel fuel E. less of certain pollutants than those burning of gasoline or diesel fuel
答案选择E,我是理解的,因为有了those指代vehicles,than左右对称,且句意正确。 但不明白的是为什么是less呢?pollutant在这里不是复数么? 而且查了字典发现pollutant可以是cn或者unc的。
请达人指教,多谢。 |