Asthereislessandlesscoalandoil,scientistsareexploringnewwaysofmakinguseof____energy,suchassunlight,windandwaterforpowerandfuel.
A.primaryB.alternativeC.instantD.unique
正确答案:B
Asthereislessandlesscoalandoil,scientistsareexploringnewwaysofmakinguseof____energy,suchassunlight,windandwaterforpowerandfuel.
A.primaryB.alternativeC.instantD.unique
正确答案:B