First, read the English article below.

The occasion for the speech can go a long way in helping you determine the topic. Your speech topic will vary depending on whether the occasion is celebratory, just plain fun, solemn, or professional. Here are a few ways that the occasion can help influence your speech topic:  If the occasion is solemn, such as a funeral or memorial service, then your topic should be serious and relevant to the occasion. If the occasion is fun, such as a toast at a bachelor party, then it's time to bring out the fun anecdotes and stories and to make people laugh -- not to share your passion for coin collecting. If the occasion is celebratory, like a wedding, then you need to provide some light-hearted humor as well as some serious and sentimental points. If the occasion is professional, then you need to stick to a professional topic, such as website design, and not focus on your personal experiences. Your purpose is related to the occasion and is the goal you want to achieve through your speech. Your purpose can be to inform, persuade, or just to entertain your audience. A speech can have a variety of purposes, but it's important to be acquainted with the most common purposes:    To inform. To inform your audience, you'll need to provide relevant facts and details about a subject that reveals information that allows your audience to see an ordinary subject in a more complicated light, or to learn about a completely foreign subject. To persuade. To persuade your audience, you'll need to use rhetorical techniques, metaphors, and convincing evidence from experts to show them that they should do something, whether it's to elect you for office, recycle more, or take the time to volunteer in their communities. To entertain. To entertain your audience, you'll need to draw on personal or anecdotal examples, tell funny stories, show off your wit, and make your audience crack up, even if you're communicating an underlying serious message. To celebrate. If you're celebrating a specific person or event, you'll need to show your audience... 

Now, please write a short abstract for it in Vietnamese. Abstract:
Cân nhắc sự kiện. Cân nhắc mục đích của bạn. Tránh những chủ đề không phù hợp.