are that boy's shoes dirty?为什么boy后面加's

The boy comes from china,为什么come后面加s? The boy's dirty face looks_______(fun) that's my boy These are that boy's caps.对that boy's caps提问 ______ ______ t Who’s that boy是什么意思 Who's That Boy 歌词 译：That's a boy the boy eats an apple的吃为什么加s three more boy another three boy哪一个加S Who's that boy?(同义句转换) 请回答这道提： who's that boy? What's gone with that boy?