1a) present and combine different kinds of media elements in an
        integrated way.
1b) graphics, sound, music, animation and video.
1c) small in size,	 less than that of a book
1d) It means that a computer can respond to the users and the 
        users are also able to see what they want in their requested
        order.
2.   animal screams
       MIDI music	birthday song
       video		golden fish
       graphics	Hong Kong scenery
       text		poem
3a) Ten Thumbs Typing Tutor 2.4
3b) Ten Thumbs Typing Tutor teaches 
         the skill of touch typing in an accessible step-by-step way
         Features include: network support, a range of feedback
         options, and automatic weighting of lessons to get you
         learning most effectively. 
3c) texts, sounds, animations, graphes
3d) Yes.
3e)  It includes many kinds of media.
          It has interactive user interface.
3f)   It content is hard to copy.
         We must use a computer to retrieve the information.