/userfiles/361001000001210165/files/2_2_3%e5%90%91%e9%87%8f%e6%95%b0%e4%b9%98%e8%bf%90%e7%ae%97%e5%8f%8a%e5%85%b6%e5%87%a0%e4%bd%95%e6%84%8f%e4%b9%89.ppt