单项选择题
A.effective B.efficient C.sufficient D.supplement
Methanol’s most attractive feature is that it can reduc...
单项选择题Methanol’s most attractive feature is that it can reduce（）about 90 percent the vehicle emissions.
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
