Question

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

Answer 1

B.

考查形容词。既然石油和煤都越来越少，人们只好使用一些其它可替代这些燃料的东西，alternative 有“可选择的，可替代的”之意，符合句意。primary“首要的，初期的”，instant“立即的，迅速的”，unique“独特的”。