PTE Re-tell Lecture 真实讲座练习题: 重力是什么?

在PTE中,无论是Summarise Spoken Text 还是 Re-tell Lecture的考题大都是从真实的讲座或者演讲中截取的,中间经常经常夹杂很多不同的环境音.很多同学都反映有时未必是听不懂,而是听不到. 鉴于此,墨尔本文波雅思PTE专门为大家总结了真实讲座的PTE练习音频,相比新闻音频来说,整体更加接近PTE考试的真题,内容方面,我们也会为大家提供考试中存在的近似题,最近我们会持续更新,敬请期待!


We’re all familiar with gravity as ‘’the reason objects fall’’, but there is much much more to gravity than that. Gravity is a long range attractive force between all objects with mass. It’s what keeps us from falling off the earth, it’s what keeps the earth in orbit around the sun and it’s what caused the sun itself to form four and a half billion years ago. It’s amazing to think that every massive object attracts every other in the universe. That means that your dog, the earth and a black hole in the Andromeda galaxy 2.5 million light years away are all gravitational attracted to you and you to them. In the 17th century, Issac Newton discovered that the strength of the gravitational force decreases by the square of the distance between two objects– so if you are twice as far away, gravity is only 1/4 as strong. He also discovered the strength of the gravity is proportional to the mass of the objects in question: the more massive an object, the stronger the gravitational force. That’s why we can all feel the Earth pulling on us, but don’t really notice the pull of the moon. It’s small and farther away. The moon’s gravity is strong enough to cause the tides though. And when I said earlier, the gravity is an attraction between objects with mass and white line. I meant objects with energy because in addition to massive objects, gravity also attracts light and other massless but energetic particles, so that a photon of light can be bent slightly passing the sun, or trapped completely by a black hole. Now do you understand the gravity of the situation?

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