Please open the above powerpoint file of "Wave" to view.

    After viewing the above  powerpoint of "wave" in the topic of "Wave",

    answer the following questions 1 thru 2 before coming to the class.

    [Note] (a) When you click the powerpoint file to open it,  you can choose "slide show" on the top menu in the powerpoint, then select " show from the beginning". then you should choose the "enable the content", then view the content of powerpoint.  (b)AFter you complete viewing the content of powerpoint file, you can hil the escape key from the keybaord in the computer, then choose" NOT to save the file", then close the power point file.


    1. What is a wave?

    2. How many kinds of waves are there? What is the difference between them?