This is (the one/what) I wanted.为什么不能用which

This Is The One 歌词 one more ,this is the fifth This is one of the ____watches.(run) This is the one I wanted . This is one of the _______watch(run) this one really is out of the This dress is one of the ( visit ) this one is (small)than the first one 7. I don't feel very well. Mum asked me _____ this morning. （重庆市） A. what the matter is B. wha this yellow coat is mine.the red one is y_____ life is difficult,this is one of the greatest---(ture) 10.This is the only one of the books published Is this the calculator___you borrowed from Jane?the one what this is the --- that one can find at the market. Of all the shops,this one is the _____(bad) This one is the b( )among them,but that one is the smaller Is this the one I gave you可以说成Is this I gave you the Is this the first factory the one some foreigners visited yesterday?为什么用THE ONE?