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(one's) 20s; twenties
二十にじゅう代だいで結婚けっこんした。
I got married in my twenties.
彼かれは二十にじゅう代だい前半ぜんはんの男性だんせいだ。
He is a man in his early twenties.
彼女かのじょはまだ二十にじゅう代だいなのに立派りっぱだ。
She is admirable, even though she is still in her twenties.