回複：關於H1B簽證一問

Unless you have PR of certain countries (whose citizens get visa waiver for B visas), and get visa stamp at that country you are a PR. Otherwise,for US consular officers to do their job right, they should NOT give you M-entry, long term visa stamp.
Because there is a published standard of the length and number of entry to give to all countries based on the reciprocal treaty. US citizens need visa to enter China (mainland) and PRC citizen get limited and shorter visa period at a US consulate.