Questions 45 to 48 are based on the following passage: (2004版第六课The Art of Public Speaking) There are many similarities between public speaking and daily conversation. The three major goals of public speaking - to inform, to persuade, to entertain - are also the three major goals of everyday conversation. In conversation, almost without thinking about it, you employ a wide range of skills. You organize your ideas logically. You tailor your message to your audience. You tell a story for maximum impact. You adapt to feedback from your listener. These are among the most important skills you will need for public speaking. Of course, public speaking is also different from conversation. First, public speaking is more highly structured than conversation. It usually imposes strict time limitations on the speaker, and it requires more detailed preparation than ordinary conversation. Second, speech requires more formal language. Listeners react negatively to speeches loaded with slang, jargon, and bad grammar. Third public speaking demands a different method of delivery. Effective speakers adjust their voices to the larger audience and work at avoiding distracting physical mannerism and verbal habits. One of the major concerns of students in any speech class is stage flight. Actually, most successful speakers are nervous before a speech. Your speech class will give you an opportunity to gain confidence and make your nervousness work for you rather than against you. You will take a big step toward overcoming stage fright if you think positively, choose speech topics you really care about, prepare thoroughly, and concentrate on communicating with your audience. Like many students over the years, you too can develop confidence in your speech abilities. Because speech is a form of power, it carries with it heavy ethical responsibilities. Ethical speakers use sound means to achieve sound goals. They do this by being well informed about their subjects, by being honest in what they say, by using sound evidence, and by employing valid reasoning Public speaking and daily conversation are different because: