资料来源 : pyDict

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资料来源 : WordNet®

up on
     adj : being up to particular standard or level especially in being
           up to date in knowledge; "kept abreast of the latest
           developments"; "constant revision keeps the book au
           courant"; "always au fait on the latest events"; "up on
           the news" [syn: {abreast of(p)}, {au courant}, {au fait},
            {up on(p)}]