1.ray的基本意思是“光束,光线”,一般指发光体如太阳或月亮等发出来的光线,也可作“射线”解,指热、电或其他形式的能的射线,用作这两种意思时,常以复数形式出现。
2.ray还可作“一线”解,常与a与of连用,意思是“一线…”,表示微量、丝毫。
3.ray用于比喻可指“智慧之光”。

a ray of sunshine
给某人的生活带来光明或快乐的人或事情 person or thing that makes sb's life brighter or more cheerful
Her visit brought a ray of sunshine into the old man's life.她的来访给这位老人的生活带来了欢乐。

In summer the sun's rays come to us much more than they do in winter.夏天的日照要比冬天的多。
He focused the sun's rays on a paper with a burning glass.他用一面凸透镜把阳光聚焦在纸上。
What prevents rays from entering your eyes?什么阻止光线进入你的眼睛?
The light rays from the sun light up the globe.太阳射出来的光照亮全球。
The doctor advised him to bathe in the sun's rays.医生劝他多晒太阳。
London lay before us in the soft mellow rays of the moon.伦敦在柔美的月光下展现在我们面前。
Cathode rays are attracted by a positive charge.阴极射线被阳电荷所吸引。
The doctor followed up Billy's operation with x-rays and special exercises to make his foot stronger.医生给贝利做了手术,又进一步做X射线检查,并让他做了一些特殊的锻炼,以使他恢复脚部功能。
There isn't a ray of hope left for us.我们连一线希望也没有了。
This gave a ray of courage to the oppressed and poor.这为受压迫的穷人增添了一丝勇气。

ray, beam
这两个词的共同意思是“光线”。其区别是:
1.beam指由日、月、灯或激光器等发出的有一定宽度的光线，即光束、光柱; ray指由发光体发出的成为线形的光。ray在科技术语中又指射线。用于比喻则可指智慧等的闪光。
2.在通俗用法中beam是比ray更强的光线; ray是构成beam的许多光线中的一条。例如:
There I saw the glorious beams of the rising sun.在那里我看见了初升太阳的光芒。
The searchlight sent its beam into the night sky.探照灯的灯光射入夜空。

［同义词］   beam
［词源］  ＜古法语rai(光线,辐射)