A spectrum is formed by a ray of light passing through a prism.
一束光通过棱镜就会形成光谱。
《牛津词典》
2
You all know how when you take a crystal prism and pass a beam of sunlight through it, you get a spectrum, which looks like a continuous band of rainbow colors.
你们都知道，拿起一个水晶棱镜，让一束阳光通过它，就会得到一个光谱，看起来就像一条连续的彩虹色带。
3
This light is passed through a prism, which breaks it up into a spectrum.