Hello,
I would like to apply for a 1 year multi-entry visa to China from your embassy in Singapore. I am interningat the NCAIDS (China CDC) in Beijing and currently have a Z-visa from my old company in Shanghai. So, I have to change my visa type as well. My boss suggested I apply to change to an F-visa, and has provided me with an invitation letter with stamp. She wasn't sure if F or L (tourist) would be better. Thanks for your help.