sec11-16为什么不补do?

aster1990

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

E为什么不补do? 我觉得补上更好. 不补似乎有pollutants和those... 比较的歧义.

请指教.

aster1990

看看这题吧:

sec03-09

In the United States, trade unions encountered far more intense opposition against their struggle for social legitimacy than the organized labor movements of most other democratic nations.

(A) against their struggle for social legitimacy than

(B) in their struggle for social legitimacy than did

(C) against their struggle for social legitimacy as

(D) in their struggle for social legitimacy as did（B）

(E) when they struggled for social legitimacy than has

B很明显的把did补出来了.为了避免歧义.A就是这个歧义.Choice A seems to compare struggle to organized labor movements.

请NN解答一下.

monicars

每题ETS一般就考两个知识点，除此以外的是可有可无的；省略的问题有时并非要考的点

你可以看看，第一题　是　可数与不可数的修饰和than parallesim

in OG11th,ETS shows 3 pionts.I think ETS also shows prorities of these 6 points.

纯属个人经验