扩展器是（）。

A.增加与或门的输入端数

B.增加与或门输出端数

C.作接口扩展用

The photoperiodic response of algae actually depends on the duration of darkness, but not on the response of light.

A．is not on light

B．but is’ not on the light
C．and not on light

D．the light is not on