seveal ambiguities in SC!!

schwa995

9. The proposed urban development zones do not
represent a new principle; it was employed in
"Operation Bootstrap" in Puerto Rico.

(B) represent not a new principle, but one that
(D) are not a new principle, but one that

b  
why not D? although b is correct.
b-> is equal to that represent not a new principle, but a principle that was…..
D-> the only flaw is that it changes the meaning of “represent” to “are”

16. 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
(D) fewer of certain pollutants than does burning
gasoline or diesel fuel
(E) less of certain pollutants than does the burning
gasoline or diesel fuel

e

Is The original meaning that “vehicles powered by natural gas emit less of certain pollutants than  do those powered by burning gasoline or diesel fuel.”or that “ vehicles powered by natural gas emit less of certain pollutants than does the burning gasoline or diesel fuel.”?
Why?

tongxun

非常重要！因为涉及到补不补出动词，以及句子的逻辑合理性问题。

schwa995

9.> thanks for everone's help ! It is clear to me!
16-> HOw can we identify at first glance that the sentence tries to compare the amount of the pollutions emmited by vehicles with amount of pollutions by the burning of gas. THIS ISN'T IMPORTANT ???

qiufeng1990

I think this sentence compares the amount of pollutants emitted between by "vehicles" and by "the burning of gas".

tongxun

9、the choice D can be interpreted as the ....zones are ...principle. Is zones equal to principle?
16. emit less of certain pollutants than the burning of gasoline or diesel fuel.
Just read this sentence again, we can find that vehicles powered by natural gas emit the burning of gasoline or diesel fuel.
I think that the former you mentioned would be  the origin meaning of the sentence.

maryland

9. I agree to the interpretation.
b-> is equal to that represent not a new principle, but a principle that was…..
D-> the only flaw is that it changes the meaning of “represent” to “are”

16. (E) less of certain pollutants than does the burning gasoline or diesel fuel
NOTICE that there is a conj word "or" in the sentence, so the verb should be consistent with the nearer subject. Thus single verb is required here.