What does the author mention about petroleum oil in the essay? ( )
A.Petroleum oil is a non-renewable resource, so when it is depleted human society will face a serious consequence.
B.The world economy is powered by the burning of petroleum oil.
C.Greenhouse gas emissions are the main by-product from the combustion of petroleum oil.
D.Petroleum oil liberates human labor as three tablespoons of of crude oil contain the same energy as eight hours of human labor.
正确答案:ABC
