Em co nhu cau muon mua thuoc nhung khong biet ba loai thuoc co chat luong va dung luong khac nhau the nao a. cung nhu cach phan biet hang gia hang that. Ban em co dung nhung hop mau xanh la' hoac mau nau, the thi co khac gi khong a? xin moi nguoi giup em tu van. em xin cam on a