Everything about 約炮
You cannot make this happen with 成人. It's also far more official than 大人 so It is way more typical to make use of 大人 in every day speech. Also 成人になる particularly suggests "to show 20". 大人になる usually suggests "to be experienced". 芳一は来年成人になる -> Alright“(上海国际)电影节……不仅仅有