(sharing!!) Interesting Powerpoint (PPT) rules

On Monday, Sally has shown us several rules of making a good ppt.  A year ago, I have attended to Oral-aural Drills in English class and the teacher also taught us how to prepare and demonstrate a find and suitable ppt when giving a speech.  Here is what she has shown to us, a very interesting video that the speaker pointed out some common mistake of making a wrong ppt.  By sharing this, I hope everyone can do better on ppt!