一道语法题，as well as 前后的动词不用平行吗?

Q28: PP58.

Diesel engines burn as much as 30% less fuel than gasoline engines of comparable size, as well as emitting far less carbon dioxide gas and far fewer of the other gasses that have been implicated in global warming.
        

A.      of comparable size, as well as emitting far less carbon dioxide gas and far fewer of the other gasses that have

B.       of comparable size, as well as emit far less carbon dioxide gas and far fewer of the other gasses having

C.      of comparable size, and also they emit far fewer carbon dioxide and other gasses that have

D.      that have a comparable size, and also they emit far fewer of the other gasses having

      E.   that have a comparable size, as well as emitting far fewer of the other gasses having

这道题答案是A，as well as前后的动词不用平行吗？

转贴的，大家讨论一下吧...

A: were謂語重複，應該去掉

B: correct，connected分詞修飾句子主語settlements

C: 第二個of修飾Structures不對，應該修飾scale；each同位語從句用過去完成時沒必要，

D: 第二個of修飾Structures不對，應該修飾scale；and with each沒有平行物件，

AS WELL AS既可以做连词，也可以做介词。以上题目中应该做介词，所以后面可以跟ING形式。如SHE SINGS AS WELL AS PLAYING THE PIANO.当然你把它当连词用并列形式也没错，但主要看选项有没有other obvious mistakes.