1. 这里produce的单复数应该无关. 2. 看比较的对象是否可数. 可数用fewer, 不可数用less. 这里有个ETS的trick, 比较的对象是重量, 不可数, 所以用less, 尽管重量的度量衡ton是复数. 但是比较对象不是度量衡. 还有个例子可以帮助理解: 1. 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) (E) less of certain pollutants than those burning gasoline or diesel fuel 这里用emit less of certain pollutants, 比较的是pollutants的量. 如果用fewer, 那么表达就是pollutants的种类, 比如以前有3种, 现在有2种. |