並前往https://md1.mdhs.tc.edu.tw/tp/teacher/TE229/%E7%8F%AD%E7%B4%9A%E7%B6%93%E7%87%9F/ch2-2-2%E5%8E%9F%E8%89%B2%E8%88%87%E6%B7%B7%E8%89%B2.ppt