单项选择题
A.which B.who C.what D.whose
The hydrocarbons they do emit are less likely to（）ozone...
单项选择题The hydrocarbons they do emit are less likely to（）ozone.
A.general B.generation C.generate D.generous
Ethanol is commonly used as a gasoline supplement, but ...
单项选择题Ethanol is commonly used as a gasoline supplement, but it is currently about（）methanol.
A.twice as expensive as B.twice as more expensive as C.as twice more expensive as D.as twice expensive as
At a rough estimate,Nigeria is（）Great Britain.A.three t...
单项选择题At a rough estimate,Nigeria is（）Great Britain.
A.three times as big as B.three times as bigger as C.as three times big as D.as three times gigger as
