Questions about the "F" visa

Roxan, do you go to China to visit your friend? If so, I think you should apply for an L type rather than the F type. The invitation letter should contain information about you and the friend and information about the planned visit. The "F" or "L" type usually lasts for three months. If you get a single entry permit, you can't leave the country and come back. If you get double or multiple entries, you will be allowed to leave and then back.