I am a Chinese-american, holder of an American passport. I have a one-year multiple entry visa issued to me in Hong Kong. I will be entering China at Shenzhen (from Hong Kong,) then go to Kathmandu via Tibet, then return to China via Tibet. Do I have to apply for ANOTHER Chinese visa for re-entering China thru Tibet? Even though I ALREADY Have a Chinese visa (one-yr-multiple entry) stamped on my passport? Thanks. Vic