A:①②③
B:①②④
C:①③④
D:②③④
—Da Liu, I think.
天然气和液化石油气(主要成分为C3~C8的烷烃)燃烧的化学方程式分别是:CH4+2O2CO2+2H2O,C3H8+5O23CO2+4H2O.现有一套以天然气为燃料的灶具,欲改烧液化石油气,应采用的正确措施是( )
—Excuse me, Maria. Can I use your bike?—Sure. Here you are. But you must return it _____ time.