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

因為當形容詞子句發生的時間比主要子句早時

形容詞子句不可改省略形分詞片語

我也选了B。尽管知道having been不对，但就是冲着as well as emit选的。如果A对的话，

究竟as well as怎么个用法？

顶上来

as well as到底加do还是doing