The development of industry has been gradual process throughout human existence, from stone tools to modern technology.
A. /, the
B. the, a
C. a, /
D. a, a
网友回答
A. /, the
B. the, a
(答案→)C. a, /
D. a, a
解析：考察冠词。第一空是泛指工业的发展是一个逐渐发展的过程，第二空的human existence是一个抽象的意义，故使用零冠词。故C正确。