driving(upper)(high)beam tell-tale是什么意思

用法例句

Briefly introduces the lighting requirement of car headlamp,narrates the surveying method of the upper beam,lower beam and group lamp′s character,also the train thought of confirming and how to make the light and shade closing line.

简述汽车前照灯的照明要求 ,叙述了对远光、近光以及灯具组照明特性的测量方法 ,说明等照度曲线、明暗截止线的判识和制取的思路。