bright: implies emitting or reflecting a high degree of light: one of the ~est stars in the sky.  (emit发射,mit=mis词根表示送出to send, e=ex表示向外)  (reflect反射反映，flect词根表示折弯to bend, re词根有两个意思1) 再次again, 2)往回back，这里用2)


brilliant: implies intense and often sparkling brightness: ~ diamonds.   （sparkle是无数移动闪烁的光点innumerable moving points of bright light, 如the sparkling waters of the gulf泛着光点的海湾）


radiant: stresses the emission or seeming emission of rays of light: an imposing figure in ~ armor.  （ray是一根根的光即光线, 中文中，光芒指向四面八方放射的强烈光线，光辉则指强烈的光芒，光华和光辉同意）


luminous: implies emission of steady, suffused, glowing light by reflection or in surrounding darkness: ~ white houses dot the shore.    （suffuse布满弥漫颜色水气感情等to spread over, 如a dull red flush suffused Selby's face塞尔比的脸上泛起了淡淡的红晕。 fus词根表示泼出溶化to pour out, melt, sur词根是super变体表示超出，这里变成了suf）


lustrous: stresses an even, rich light from a surface that REFLECTs brightly without sparkling or glittering: the ~ sheen of fine satin.      （光泽专指反光，本身不发光，如《后汉书·方术传下·王真》"王真 年且百岁，视之面有光泽，似未五十者"，luster是光学和地质学术语，指物体或矿物反光能力） (glitter表示闪耀brilliant sparkling,可见和sparkling意思相同，如glittering diamonds闪耀的钻石)


bright明亮: 发出或反射出大量的光，brilliant闪耀: 指明亮闪烁的光点(sparkle光点闪烁)，radiant光芒光辉: 强调发出光线，即光芒，luminous微微发光: 发出或反射微弱而稳定的光，多用于周围环境较暗，lustrous光泽亮泽: 强调光泽均匀丰富，但不闪耀


记忆方法: 1）首字母BBRLL想成白而亮<==明亮


         2）明亮的意思是发光或微微发光mean shining or glowing with light.