/ http://www.slideshare.net/images/logo.gif / 際際滷Share feed for 際際滷shows by User: lalaulis1 https://cdn.slidesharecdn.com/profile-photo-lalaulis1-48x48.jpg?cb=1523586535 The mediocre teacher tells. The good teacher explains. The superior teacher demonstrates. The great teacher inspires.��� William Arthur Ward