回复：第一次申请J-1没经验，各位帮忙看看里面的问题好吗？谢！

1. That means a copy of your diploma along with a notarial certificate indicating that is a True copy of your diploma. If your diploma isn’t in English, a notarial certificate should include a copy of your original diploma, a translation and a declaration showing the content of translation is the same as your original diploma.
2. I’m not sure about this. Probably just write your previous business address. Your previous mentor’s letter is fine.
3. Either way is fine. This is all up to you. Usually a J2 visa is valid in 6 months with 2 entries.