plain: stresses lack of anything such as ornamentation or affectation likely to catch the attention: a ~ house on a quiet street; or it may suggest elegance: the furnishings were ~ with very simple classic lines; or frugality: she sets a ~ but abundant table; or, with reference to personal appearance, lack of positive beauty that does not go to the extreme of ugliness: drawn to that ~ and kindly face.     (affectation做作矫情不真诚不自然implies speech or behavior that is not natural or sincere，如his foreign accent is an affectation他的外国口音只是装腔作势)


homely: may suggests easy familiarity or comfortable informality without ostentation: a comfortable ~ room; in application to personal appearance, it implies something between plain and ugly: a ~ mutt.   ostentation炫耀夸耀奢华


simple: very close to plain in its references to situations and things, may stress personal choice as the source of the quality described: lived a ~ life; and regularly connotes lack of complication or ostentation: gave a ~, straightforward answer to the question.


unpretentious: stresses lack of vanity or affectation and may praise a person: a soft-spoken and ~ person; but in reference to a thing may convey either praise or depreciation: an ~ and battered old car.


plain平凡简洁朴素普通: 表示不引人注意无装饰不做作；或简洁；或朴素；或形容人相貌普通不美丽也不丑陋；homely舒适其貌不扬: 表示熟悉放松舒服无束不奢华，形容人相貌时介于普通和丑陋之间，simple简单直接: 表示不繁复不炫耀，强调出于个人选择，unpretentious低调或不好看:  用于人时称赞其不虚荣不做作，用于物时也可能表示其难看


记忆方法: 1）首字母PHSU排列成PUSH推动<==平凡的世界

               2）平凡的意思是不炫耀不修饰mean free from all ostentation or superficial embellishment.   embellish表面装饰