We can not see them, coz they are not light-reflecting. 我们看不见它们是因为它们不反光。
Reflector: light-reflecting device on the back of the snowmobile. 反射:光反射装置在背部的雪橇。
Development of modified light-reflecting paints for traffic signs 改性道路标志反光涂料的研制
After the rat model of optic nerve crash was established, the eye pupil dilated, light-reflecting decreased significantly and the retinal vascular perfusion was normal. 结果:1.建立大鼠视神经夹伤模型后,当时术眼瞳孔散大,光反射明显减弱,眼底血管灌注正常。