Who do/does these books belong to?助动词用哪个正确?

Who do/does these books belong to?助动词用哪个正确? who do these books belong to?who does these book 这些钥匙是谁的who does these keys belong to?还是Who do these keys bel Who does it belong to? these keys do not belong to him.和this case does not belong t Who does this watch（belong）to? 1,who does this coat belong to? who does the watch belong to正确吗?为什么不能用whom? who do you know does the book with a red cover belong to Whose books are these?They belong to _____(we) 这句话为什么用who 不用whom啊 .who does this book belong to? does this book belong to you为什么用does?不是do