题目内容:
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
参考答案:
答案解析:
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