问题
选择题
While he was investigating ways to improve the telescope, Newton made ______ discovery which completely changed ______ man’s understanding of colour.
A．a; 不填
B．a; the
C．不填; the
D．the; a
答案
答案：A
根据语境得知牛顿的一次发现是泛指，应用不定冠词；man表示“人类”，其前不用冠词。