/ http://www.slideshare.net/images/logo.gif / ºÝºÝߣShare feed for ºÝºÝߣshows by User: kghye8933 https://public.slidesharecdn.com/v2/images/profile-picture.png ÓÐÖ¾Õßʾ¹³É If you never do, you will never know