A light (diode), is on or off, at one end, and a photo-resistor at the other end registers its state.

轻型（半导体），或者是客，一头、照片登记在另一端的电阻状态。

youdao

A light (diode), is on or off, at one end, and a photo-resistor at the other end registers its state.

轻型（半导体），或者是客，一头、照片登记在另一端的电阻状态。

youdao