2018年翻譯資格考試初級筆譯模擬題：什么是重力
漢譯英
什么是重力?
假如你把一個球往上拋，它還會掉下來。球為什么會掉下來呢?球掉下來是因為球被吸引或拉向地球。地球?qū)λ形矬w都施加吸引力。離地球較近的物體所受的吸引力，比遠離地球的物體所受的吸引力大。這種吸引力通常叫做重力。作用于地球表面上物體的引力，叫做物體的重量。
空間所有的天體，如月球﹑行星和星星，對物體也都有吸引力。物體越大﹑越重，其引力也就越大。既然月球比地球小，因此，月球?qū)υ虑虮砻嫔弦晃矬w施加的力，將比地球?qū)Φ厍虮砻嫔贤晃矬w施加的力要小。實際上，月球的引力只有地球引力的六分之一。這就是說，地球上一個重120公斤的物體，在月球上會只重20公斤。因此，在月球上你能舉起的重量，將是你在地球上所能舉起的最大重量的六倍。
地球的引力或拉力，使我們和地球上別的任何東西都不致漂浮到空間中。要飛向空間并到月球或其他行星去旅游，就必須克服地球的引力。
進入空間
怎么才能克服地球的引力呢?科學(xué)家們?yōu)榇诉M行了長期的研究。直到最近，他們才能夠制造出足以克服地球引力的強有力的機器。這種機器就稱為宇宙火箭。宇宙火箭的巨大速度和強大的動力，幫助它掙脫地球的引力而進入空間。
火箭
強大的宇宙火箭的工作原理和簡單的煙火火箭是一樣的。煙火火箭有一圓柱形殼體和一錐形頭部。殼體內(nèi)充填黑色火藥作為燃料。它是一種化學(xué)品的混合物，能迅速燃燒形成熾熱的氣體。
火箭的底部有一個通道，即噴口。從噴口伸出一根尾巴似的引信。沿殼體裝著一根長棍，用以在引信點著以前確定火箭發(fā)射的方向。
當(dāng)黑色火藥燃燒時，熾熱的氣體，即燃氣從噴口急速排出。只要黑色火藥還在燃燒，燃氣就不斷急速排出。當(dāng)這些燃氣通過噴口往下噴出時，火箭就被向上推進。這就叫做噴氣推進。圖中所示的簡單實驗，可以幫助你了解噴氣推進。
參考譯文
What Is the Force of Gravity?
If you throw a ball up, it will come down again. What makes it come down? The ball comes down because it is pulled or attracted towards the Earth. The Earth exerts a force of attraction on all objects. Objects that are nearer to the Earth are attracted to it with a greater force than those that are further away. This force of attraction is known as the force of gravity. The gravitational force acting on an object at the Earth’s surface is called the weight of the object.
All the heavenly bodies in space like the moon, the planets and the stars also exert an attractive force on objects. The bigger and heavier a body is, the greater is its force of gravity. Thus, since the moon is a smaller body than Earth, the force it exerts on an object at its surface is less than that exerted by the Earth on the same object on the Earth’s surface. In fact, the moon’s gravitational force is only one-sixth that of the Earth. This means that an object weighing 120 kilograms on Earth will only weigh 20 kilograms on the moon. Therefore on the moon you could lift weights which are six times heavier than the heaviest weight that you can lift on Earth.
The Earth’s gravitational force or pull keeps us and everything else on Earth from floating away to space. To get out into space and travel to the moon or other planets we have to overcome the Earth’s gravitational pull.
Entry into Space
How can we overcome the Earth’s gravitational pull? Scientists have been working on this for a long time. It is only recently that they have been able to build machines powerful enough to get out of the Earth’s gravitational pull. Such machines are called space rockets. Their great speed and power help them to escape from the Earth’s gravitational pull and go into space.
Rockets
The powerful space rocket works along the same lines as a simple firework rocket. The firework rocket has a cylindrical body and a conical head. The body is packed with gunpowder which is the fuel. It is a mixture of chemicals that will burn rapidly to form hot gases.
At the base or foot of the rocket there is an opening or nozzle. A fuse hangs out like a tail from the nozzle. A long stick attached along the body serves to direct the rocket before the fuse is lighted.
When the gunpowder burns, hot gases rush out of the nozzle. The hot gases continue to rush out as long as the gunpowder burns. When these gases shoot downwards through the nozzle the rocket is pushed upwards. This is called jet propulsion. The simple experiment, shown in the picture, will help you to understand jet propulsion.
