Ethanol and methanol have important advantages（）other carbon-based alternative fuels.

On the other hand, alternative fuels do have（）.A.drawba...

单项选择题On the other hand, alternative fuels do have（）.

There is a growing realization that the only（）way to ac...

单项选择题There is a growing realization that the only（）way to achieve further reductions in vehicle emissions is to replace conventional diesel fuel and gasoline with cleaner-burning fuels.

These reactions increase the probability of incomplete ...

单项选择题These reactions increase the probability of incomplete combustion and are more likely to（）uncombusted and photochemically active hydrocarbon compounds into the atmosphere.