单词	nucleus of a set
释义	nucleus of a set 集的核
随便看	root root around root beer root canal root cellar root crop root directory root for root ginger root out root vegetable root-bound rootbound rooted rooter rootin'-tootin' rootle rootless roots reggae rootstock rootsy rope rope bridge rope in rope ladder 好汉不打有理的好汉不挑肩头软，绣女不练针头重好汉不挣有数钱好汉不提当年勇好汉不敌两，好事不过三好汉不欺负受伤的老虎好汉不能叫尿憋死好汉不论出身低好汉不赶乏兔儿好汉争气，赖汉争食どぞくどぞく【土俗】どたきゃんどたぐつどたぐつ【どた靴】どたどたどたばたどたんばどたんば【土壇場】どたキャン