SECTION　13　21

21.   According to the Better Business Bureau, if you fail to advertise the highest price in a range of prices for a service or product as prominently as that of the lowest, it violates the New York Consumer Protection Law.

(A) if you fail to advertise the highest price in a range of prices for a service or product as prominently as that of the lowest, it

here it is not that clear to refer anything.

(B) if one fails to advertise the highest price in a range of prices for a service or product as prominently as the lowest price, it

here it is not that clear to refer anything. And there is no parallel structure.

(C) failure to advertise the highest price in a range of prices for a service or product as prominently as the lowest

(D) failure to advertise as prominently the highest price in a range of prices for a service or product as the lowest

here is a little bit triky to cause the parallelism error happens between the lowest price to advertise and  failure to advertise

(E) failing to advertise as prominently the highest price in a range of prices for a service or products as that of the lowest

that of should be omitted since the comparison is between the highest price and the lowest price

请问　A　B两项是不是因为太口语化才不选的　　D　E　又错在哪里？

7.     Since the 1930’s aircraft manufacturers have tried to build airplanes with frictionless wings, shaped so smoothly and perfectly that the air passing over them would not become turbulent.

(A) wings, shaped so smoothly and perfectly

(B) wings, wings so smooth and so perfectly shaped

(C) wings that are shaped so smooth and perfect

(D) wings, shaped in such a smooth and perfect manner

(E) wings, wings having been shaped smoothly and perfectly so

A为什么错了？？