英语听力：自然百科 Spacewalks 太空行走，看上去很美
时间：2019-01-22 作者：英语课 分类：自然百科2008年
From planetary orbit, the earth and heavens look serene 1. But the vacuum of space is a hostile environment, lacking oxygen and permeated 2 by radiation. Since the advent 3 of manned space flight in the 1960s, humankind has been exploring this inhospitable realm from the relative safety of spacecraft. But occasional extravehicular activities have led astronauts to leave these confines and explore the unknown. In order for astronauts to survive in space, spacesuits provide a self-contained environment. Their tough material, along with heating and cooling elements, protect astronauts from extreme temperatures, ranging from around 250 degrees Fahrenheit 4 to minus 250 degrees. The suits are pressurized with pure oxygen, allowing astronauts to breathe and keep their blood from boiling in the vacuum of space.
The first venture outside the spacecraft was made by Soviet 5 cosmonaut Alexey Leonov in 1965, lasting 6 only 12 minutes. This feat 7 was duplicated a few months later by American astronaut Edward White during the Gemini 4 mission. Although these excursions were meant to test the feasibility of humans to exist outside the spacecrafts, spacewalks have become a relatively 8 common part of missions in the space shuttle era. On spacewalks, astronauts have performed vital tasks that could not be accomplished 9 from inside the shuttle. They've been able to recover lost satellites, restoring them to their proper orbit. They have serviced orbiting bodies, like replacing the solar panels on the Hubble Space Telescope. And they have become the construction crew for the International Space Station.
Conducting spacewalks is dangerous, and astronauts work in pairs, tethered to the spacecraft for safety. Walking in these spacesuits is not as easy as it seems. The thick pressurized gloves make grasping tools difficult, while the weightlessness of space creates its own issues. To ensure spacewalk missions are successful, astronauts practise their planned excursions at NASA’s Neutral Buoyancy Laboratory. Immersed in a tank of water, the astronauts neither sink nor float, creating a sensation close to weightlessness. For every hour a task is scheduled on a mission, up to 10 hours is spent practising underwater.
As NASA moves forward on the maintenance and construction of the International Space Station, spacewalks will continue to be vital to the process.
- He has entered the serene autumn of his life.他已进入了美好的中年时期。
- He didn't speak much,he just smiled with that serene smile of his.他话不多，只是脸上露出他招牌式的淡定的微笑。
- The smell of leather permeated the room. 屋子里弥漫着皮革的气味。
- His public speeches were permeated with hatred of injustice. 在他对民众的演说里，充满了对不公正的愤慨。
- Swallows come by groups at the advent of spring. 春天来临时燕子成群飞来。
- The advent of the Euro will redefine Europe.欧元的出现将重新定义欧洲。
- He was asked for the boiling point of water in Fahrenheit.他被问到水的沸点是华氏多少度。
- The thermometer reads 80 degrees Fahrenheit.寒暑表指出华氏80度。
- Zhukov was a marshal of the former Soviet Union.朱可夫是前苏联的一位元帅。
- Germany began to attack the Soviet Union in 1941.德国在1941年开始进攻苏联。
- The lasting war debased the value of the dollar.持久的战争使美元贬值。
- We hope for a lasting settlement of all these troubles.我们希望这些纠纷能获得永久的解决。
- Man's first landing on the moon was a feat of great daring.人类首次登月是一个勇敢的壮举。
- He received a medal for his heroic feat.他因其英雄业绩而获得一枚勋章。
- The rabbit is a relatively recent introduction in Australia.兔子是相对较新引入澳大利亚的物种。
- The operation was relatively painless.手术相对来说不痛。
- Thanks to your help,we accomplished the task ahead of schedule.亏得你们帮忙,我们才提前完成了任务。
- Removal of excess heat is accomplished by means of a radiator.通过散热器完成多余热量的排出。