替代燃料

alternative fuel

to substitute for / to take the place of / to replace / for / on behalf of / to stand in for

to substitute for / to replace / to supersede

to substitute / to act on behalf of others / to replace / generation / dynasty / age / period / (historical) era / (geological) eon

to burn / to ignite / to light / fig. to spark off (hopes) / to start (debate) / to raise (hopes)

fuel

material / stuff / grain / feed / to expect / to anticipate / to guess