Refrection of light

It is FALSE.

Notice the keyword "MUST in the sentence. Light ray incident normally onto the surface of an optically dense medium doesn't have any directional change after going into the medium.

錯,因為個"must"
如果光係90度射入去咁就會一樣90度出番嚟,唔會改變`

無refrection
只有reflection/refraction

but anyway
無論reflection定refraction
The sentence must be wrong.
As the direction won't change if the angle of incidence is 0 degree.

冇呢個字，一係reflection，一係refraction，你係問咩嘢﹖

Refrection of light ?

Wrong Word > Reflection