单项选择题
A.of B.in C.on D.by
It is currently about（）as methanol.A.twice as expensive...
单项选择题It is currently about（）as methanol.
A.twice as expensive as B.as twice expensive as C.as expensive twice as D.expensive as twice as
Ethanol and methanol have important advantages（）other c...
单项选择题Ethanol and methanol have important advantages（）other carbon-based alternative fuels.
A.on B.over C.by D.with
On the other hand, alternative fuels do have（）.A.drawba...
单项选择题On the other hand, alternative fuels do have（）.
A.drawbacks B.setback C.drawer D.backward
