Ask XiaobaiTu and others:H1B multi entry - reentry USA

With multiple entry H1B I94 valid till 2011, if travel to china, when coming back to USA, can we still retain and use that I94 card?

My attonnery told me the I94 card might be taken, therefore I should bring all my documents for re-admission.

The problem is my original I797 H1B approval orginal notice is lost while applying for chinese visit visa. They agent asked me to attach it with my application. Can I use the copy with my other support document in this case if need when enter to USA again?

BTW, Canadian only have I94 cards, and no visa stamps required to entry USA

Any suggestion?

Thanks for your helps.