You can switch among the different sources results by selecting a source on the right of your search results. 通过选择搜索结果右侧的源可以在不同源的结果之间进行切换。
He observed that when light from a single source is separated into two beams, and the two beams are recombined, the combined beams produce a pattern of light and dark fringes. 他发现，把一束同源的光分成两束，再把这两束光重新组合在一起，组合的这两束光将产生具有明暗条纹的图样。
