谁能给我讲解一下和could never have done 的相关知识?

谁能给我讲解一下和could never have done 的相关知识? could never have done could never have done 造句 谁能讲解一下国际贸易中海运提单的相关知识? 谁能给我讲解一下这段话 这里的could never have done表示什么 can have done和could have done的问题, can have done 和could have done 的区别 could have done和would have done的区别 should have done和could have done的区别? could have done 和 might have done 的区别 谁能给我讲解一下汽车的工作原理,