什么时候用fifty-year-old这种形式什么时候用fifty years old这种形式?

什么时候用fifty-year-old这种形式什么时候用fifty years old这种形式? 英语...什么时候是year old 什么时候是years old my mother is fifty years old 用所给词的适当形式填空：1.I______(be)twenty years old next year. the old couple marry fifty years ago.这句话对吗 His father is fifty-eight years old同义句 he became famous around fifty years old这道题怎么改错? My father is(fifty years old)?对括号部分提问 适当形式：You __were__(be) thirteen years old last year. 就划线部分提问 Our teacher is fifty years old （划线部分years old） 他是一个十岁的男孩怎么翻译?years old ,year old 在什么时候不加s? “-year-old” “years old”