Carbon dioxide ___ from burning fuels is
题型:选择题
问题:
Carbon dioxide ___ from burning fuels is the most common of the so-called greenhouse gases.
A.producing
B.having been produced
C.to be produced
D.produced
Carbon dioxide ___ from burning fuels is the most common of the so-called greenhouse gases.
A.producing
B.having been produced
C.to be produced
D.produced