Your browser does not seem to support JavaScript. As a result, your viewing experience will be diminished, and you may not be able to execute some actions.
Please download a browser that supports JavaScript, or enable it if it's disabled (i.e. NoScript).
@bo 非常感谢，找到了！
哪里能下载到ppt呀，视频有一些模糊，看不太清楚，谢谢！