Question

 Many people agree that ______ knowledge of English is a must in _______ international trade today.

A．the, an

B．a, 不填

C．the, the

D．不填, the

Answer 1

B

knowledge 虽为不可数名词，但其前却可用不定冠词，表示某种程度的知识，有类似some的意思；第二空不填冠词，是因为trade 为不可数名词，表示泛指时不用冠词。