因为sc会介绍吧？但是看到一篇文章这么说：
Don’t just launch into the substantive portion of your presentation;
introduce yourself to your audience. Explain who you are, the evolution of
your interest in the area or topic, and provide some general guidelines (e.g
., should the audience interject questions during your talk or hold their
comments until the end). http://www.psychologicalscience.org/observer/style-and-substance-twelve-tips-for-a-better-job-talk#.WHHZjVUrLIU
谢谢指教！
