the key to do和the key to doing的意思和区别

the key to do和the key to doing的意思和区别 the key to doing还是do? the key to do sth .the key to doing.哪个结构是正确的? the key to 后加do还是 doing? the key to the to表从属关系时和for的区别,例如the key to the door the receipt to my case the key to your the key to happiness Does jill take the key to the front door和Can I have the key the way to do 还是doing the key to do 还是doing 还是两个都可以,搞不懂,求解释 the key to the door You are the key to my heart!的意思是什么?