whiten: implies a making white or whiter, often by a surface application: the snow fell softly, ~ing the roofs and streets.   application应用，简称APP，将某物应用于实际，surface application表示用某物使表面变白

blanch: implies a whitening either by the removal of color: ~ed when she saw the accident; or by preventing it from developing: ~ celery by covering the stalks with earth.    通常表示因惊吓而脸色变白大惊失色，如many people blanch at the suggestion听到这个建议很多人脸都吓白了; 如the girl blanched with fear when she saw the bear coming那女孩见熊向她走来, 吓得脸都白了      celery芹菜  stalk草本植物枝干


bleach: implies the action of light or chemicals in removing or reducing color: ~ hair with peroxide.          peroxide氧化氢漂白剂，双氧水        如if you will bring the soap, I will bring the bleach是一首诗"Romeo and Juliet"的结尾


decolorize: implies the deprivation of color by a process such as bleaching or blanching: a process to ~ raw sugar.  (process过程、进程是有起点和终点，可以分步骤分阶段进行的一系列动作，如the process of aging衰老的过程，如The Middle East Peace Process中东和平进程，如windows等操作系统任务管理器显示当前正在运行的processes进程)  如ethane decolorizes bromine water乙烷使溴水脱色


etiolate: is a scientific term chiefly in reference to plants from which sunlight has been excluded and the natural coloring of chlorophyll has not been formed: ~d plants look sickly.


whiten变白: 指表面变白，blanch脸色煞白，植物不见阳光而变白，除去颜色: 指除去已有颜色或防止颜色产生，bleach漂白: 用化学制剂或光照，decolorize脱色:  指除色的一个过程，如脱色漂白(的过程)，etiolate: 科技词汇，指隔绝阳光使叶绿素无法产生


记忆方法: 1）首字母WBBDE排列成WE BBD我们白白的<==变白

         2）变白的意思是从原有颜色变为白色mean to change from an original or natural color to white or nearly white.