"I am going to give a very important speech whose topic is fresh meat." The phrase "I am going to" tells me you've already planned the speech and you know what you want to say. Are you in fact looking for more ideas? If you tell us the ideas you already have, we can guide you a bit more.

1) Rehearse. Take the time to give your speech, _at least once_, standing up. If I were making an important speech, I would make a video of myself rehearsing. It's always unpleasant watching a video of yourself but it's amazing how much you learn. Usually I'll spot at least one obvious problem that I can easily correct. 2) One rule is "know your audience." Do you know _anything_ more about them other than that they are Americans? 3) It is so common to have three main points that your audience will unconsciously expect it, so have three main points. The structure people expect is an introduction, three points, and a conclusion. My personal advice for a speech this short is not to waste time on jokes or "credibility statements," but do follow the pattern "Tell them what you're going to say, then say it, then tell them what you said." Is the topic really just "fresh meat?" Or, if you are Chinese and addressing people in the U.S., is the topic "China's ban on importing U.S. beef," or a complicated situation regarding U.S. importation of chicken from China? ^^^^^^^^^^^^ Oops! I'm leaving this in so you can see that I misunderstood you. I thought you were actually going to make a speech about fresh meat. You aren't going to speak about fresh meat, you are going to speak about "Fresh Meat." When writing, you need to put the words "Fresh Meat" in quotation marks and capitalize them to make clear that it's a title. In speaking, the first time you use the words you need to identify it as a title, by saying something like "the British TV series, 'Fresh Meat.'"

Go search Youtube TEDx videos with the similar time span. That would help! Good luck for the speech.