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PS:46秒左右有破折号

You not only get the audience's attention immediately, but you feel confident during what can be the most frightening part of the presentation. After that, you can start using your notes. So the first step is to write those notes. Write the whole presentation out just like an essay. Then select the key points. But read the full version over and over again until it's imprinted on your mind. The next step is to buy some small white postcards, and write no more than one or two of the key points or key phrases onto each one. Now visual aids, like overhead transparencies, are very important of course. But most people put far too much information on them. Don't - because it's difficult to read and it bores the audience.