小白兔, and others please help. New Canadian with H1b visa on Ch

Hi,

I was a PR in Canada when I got my H1B visa on my Chinese passport. Now I will have my oath and then become a Canadian. So could you please help me with the following questions?

1. After oath, I am a Canadian, which means my China passport is invalid and I don't my PR card with me. So is the H1B stamp on my China passport still valid?

2. I need to go back to USA immediately after oath. So when on boarder, what documents should I present to get in USA? Are my H1B and I-94 on INVALID Chinese passport enough? or Should I have a Canadian passport at that point?

3. Will I get new I-94 and new H1B visa on my Canadian passport when entering the USA? or from now on, every time will I bring two passport (Chinese with H1b and Canadian) with me?

In a word, what will happen to me when entering the USA as a fresh Canadian with a H1B stamp and I-94 on my Chinese passport?

Thanks a million!!!