/ http://www.slideshare.net/images/logo.gif / ºÝºÝߣShare feed for ºÝºÝߣshows by User: drtrungthanh1 https://cdn.slidesharecdn.com/profile-photo-drtrungthanh1-48x48.jpg?cb=1523480123 "Trung thành là tốt,không trung thành còn tốt hÆ¡n'' Hai Thành