There has been ____rising demand for grain as ____industrial material in spite of the nation’s good harvests. A./;an B.a;an C.the;an D.a;/
答案:B 解析: :Demand作为要求和请求时为可数名词;作为需要需求时为不可数名词,在惯用法中既可以说much demand,也可用 great/rising等形容词修饰,此时前面用不定冠词。Material与此类似。