[求助] 请教一道白勇语法题

2. Byron possessed powers of observation that would have
made him a great anthropologist and that makes his letters as a group the rival of the best novels of the time.

(A) makes his letters as a group the rival of

            (B) makes his letters as a
group one to rival

(C) makes his letters a group rivaling

            (D) make his letters as a group
the rival of

(E) make his letters a group which is the rival of

10. 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

1）这里的that是和powers of observation后的that并列，所以要用复数，排除ABC

2)make sth sth， 排除E

选D

个人感觉POLLUTANT不可数，故用less，（但是pollutant+s不知道如何解释）,但是只有E中的those(指那些烧汽油和燃油的机器)才能和前面的vehicles比较.

如有错误请指正

pollutants加了s了，就是可数，

这里考词性比，emit + noun作宾语，less名词, fewer adj.

those burning gasoline or diesel fuel

明确表示主语比，只有vehicles才能是burning gasoline or diesel fuel动作的发出者