most efficient way to understand thousands of new words is to gain good knowledge of bas

most efficient way to understand thousands of new words is to gain good knowledge of basic word information.
A. A; a.
B. The; /
C. A; /
D. The; the

(答案→)A. A; a.B. The; /C. A; /D. The; the解析：考查冠词。第一空的a与most连用表示，非常，十分；第二空是固定词组gain a good knowledge of掌握…；句意：一种理解单词非常有效的方法就是掌握基本的构词法。故A正确。

感谢回答，我学习了