Per my inquirement, I got a letter today as following
Your case is pending visa availability. Your priority date is 8/4/04 and visas for that category are currently available for the priority date of 1/1/00. Your case will not be worked until a visa becomes available. you may wish to check the visa bulletin in the future to see when a visa will become available. Until a visa becomes available, you will not need to contact USCIS again about your case.
My case should be EB1. is it possible that they made a mistake about the category of my case?