天然气到2030年将取代煤炭

efficient – adj. capable of producing desired results without wasting materials, time, or energy

scenario – n.a description of what could happen

emission – n.the act of producing or sending out something (such as energy or gas) from a source

fossil – n.something left in or on the ground from ancient times

consumer– n.someone who purchases goods or uses something

scenario– n.a written description of a story or a series of developments

fracking –n. a method used for getting oil and gas from underground rocks by injecting liquid into the rocks so that they break apart

gigatonnes – n.a unit of explosive force equal to one billion tons of TNT