1.課本76-79https://www.youtube.com/watch?v=obgng5McDJ0

2.補充影片https://www.youtube.com/watch?v=qyGnYxYhLF0

                https://www.youtube.com/watch?v=L8In8Z-uMfU

                https://www.youtube.com/watch?v=na_iulMWkFg