调暗液晶显示屏亮度 用英语怎么说啊

Darken the LED或
Decrease the brightness of LED

turn down the LCD screen brightness

dim/reduce the brightness of LCD

dark the brightness of the LCD

正确的说法是：reduce the brightness of the LCD screen.

turn up, turn down只用来说灯光、音量等，不适用于LCD屏幕，电视机屏幕等。

调暗液晶显示屏亮度
Reduce down the LCD screen brightness