回複：That is called following-to

you need to submit I824. Then, mail you and your wife passport copies, 485, approaval notice copy for 140, 485, 824, green card copy, marrage cert., birth cert., w2 form and tax form of past three year, etc. (all non-original must be notarized) with a cover letter to Guangzhou to request. the list maybe incomplete, though. good luck