As there is less and less coal and oil, scientists are exploring new ways of making use of _______ energy, such as sunlight, wind and water for power and fuel.
A.primary B.alternative C.instant D.unique正确答案B
As there is less and less coal and oil, scientists are exploring new ways of making use of _______ energy, such as sunlight, wind and water for power and fuel.
A.primary B.alternative C.instant D.unique正确答案B
