英文版的光的折射定律

1 The incident ray, the refraction ray, and the normal to the surface all lie in the same plane.
2 The path of a ray refracted at the interface between two media is exactly reversible.
3 The ratio of the sine of the angle of incidence to the sine of the angle of refraction is equal to the ratio of the velocity of light in the incident medium to the velocity of light in the refracted medium.

楼上有语法错误，难道原文如此？

一定要英文版