While he was investigating ways to improve the telephone,Newton made discovery w
来源：网络
时间：
推荐文章
While he was investigating ways to improve the telephone,Newton made ________ discovery which completely changed ________ man's understanding of color．
A.a;/
B.a;the
C./;the
D.the;a
试题答案
A
解析：discovery发现，前加不定冠词表泛指；第二空后man一词的单数形式且前无冠词，意为“人类”。