Guangzhou Powder Milk

Hello Sir
thanks a lot for information in this web i like to visit china Guangzhou with my friend we are not Chinese, one of our Chinese friend ask us to bring powder milk for his son my i read here in web can bring 6/cans 800gm .

# 6cans for each passenger ?

# it should have any kid passenger with us?

# need to bring any milk invoices with us?