n.成熟；老成
His behavior is not particularly adult. 他的举止行为还不太成熟。
His behaviour is not particularly adult. 他的举止行为还不太成熟。
She's doing a project on adult education. 她正在进行一项有关成人教育的研究。
He'd spent all his adult life in the army. 他的成年生活全是在军队里度过的。
They enjoyed stories about adult naughtiness. 他们喜欢有关成年人顽皮的故事。
