回複：回複：回複：H1想回國, 被拒簽的機會大嗎? 需要哪些

you can make appointment by calling their call center, but you need to buy a phone card from them first. Check US embassy website for detail information.
Which consulate is not a problem, I did in Guangzhou and my firend did in Beijing. Also I have friend who get his visa in Mexico.
One or two minute you will get the visa, but you have to wait for 4 hours without sitting for a second.