"the current middle-class norm of two children per family"
"it set the norm for American homes"
Every expression of his..became a norm for the party.
In her days some kind and degree of religious belief and practice were the norm.
When group members deviate from the norms, various kinds of persuasion..are exerted in order to make them conform.
牛津高阶第八版
美国韦氏词典
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维基百科 (自由的百科全书)