Asthereislessandlesscoalandoil,scientistsareexploringnewwaysofmakinguseof_______energy,suchassunlight,windandwaterforpowerandfuel.
A.primary B.alternative C.instant D.unique正确答案B
Asthereislessandlesscoalandoil,scientistsareexploringnewwaysofmakinguseof_______energy,suchassunlight,windandwaterforpowerandfuel.
A.primary B.alternative C.instant D.unique正确答案B