听力原文： When you're making a presentation, your posture can affect the quality of your voice. The way you stand, you know, the position of your head, neck and shoulders and feet and so on is important. Check that you feet are parallel and apart and you weight is slightly forward on your feet. Make sure that your knees are relaxed, as if you are tense your back will suffer. Pay special attention to your head. Look straight ahead and don't push your neck out or drop it on to your chest. I had a man come to see me once as he was constantly losing his voice. It was all due to his habit of sticking his neck forward which was putting pressure on his throat. He sounded quite squeaky when he spoke. What he should have been doing was keeping his ears in line with his shoulders. Your head should feel as though it's floating on top of your body! So watch that. Now most of us feel quite nervous before we speak in public. You'll feel better if you spend some time dealing with the tension. It's a good idea to try and think about what it is that's making you feel this way, That way you can have some control over it. Next, try and locate the area of tension in your body. Often it's your neck or your shoulders. Then concentrate on massaging these parts and consciously trying to relax them. Believe me, it works! Let's think about what you say, now. To maximize your performance make sure you are well-prepared. Look over your notes, practise what you want to say, preferably out loud, and then, perhaps most important of all, try to feel you really want to share your subject with your audience. If you feel and share your enthusiasm with them, you're more than half way there. Remember that how people feel about you and what you are saying to them will depend on your body language. There are three main behaviour types: Passive, Aggressive and Assertive. You can use any of these types, although I think the assertive posture is one that suits most occasions best. The passive body type has a withdrawn posture. You may fidget a bit with your hands and hair. In fact I remember a well-known politician who whenever he was speaking would constantly massage the top of his head. So be ware of those funny little manner isms. They can become intensely irritating to an audience. If your posture is aggressive, however, you tend to be quite rigid. You could be constantly swinging your leg or crossing your arms and clenching your fists and the audience will fell uncomfortable. Your voice will often sound harsh or sharp and your audience may then feel quite aggressive towards you and that's something you don't want if your aim is to get them to see your point of view. That brings me to the assertive posture. Now you're standing straight, feeling comfortable and calm with your arms hanging loosely at your sides. In this position there is minimal tension and your voice is full, clear and varied. You're a delight to listen to. Finally, a few do's and don'ts when it comes to looking after your voice, especially before giving a speech or whatever. It's a bit obvious but avoid smoky areas, and alcohol, too. Drink plenty of fluids, especially things like fruit juice or even coffee or tea and keep your throat moist while you're speaking. Also, interestingly enough, stop eating too many dairy products when you have a cold. It can make you sound worse—and also don't forget to use your lips and tongue carefully to make the words stand out clearly. And just a final reminder. We can't always control the room we are speaking in. So, if a plane goes over, don't shout. Wait till it's gone. Don't battle with things you can't do anything about. If your throat feels uncomfortable, try not to cough violently or clear your throat. Just swallow instead. It doesn't always work but it's much better for your voice. That's it, ladies and gentl