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

下列选项中，不属于“六禁”内容的是( )。

A．金禁

B．嬉禁

C．徒禁

D．徙禁