问题描述：
英语翻译
这是原文
Ballooning-(III)
Today,balloons play a very important part in scientific research.
Balloons carry heavy scientific instruments up to the edge of Earth's atmosphere.The instruments measure the temperature,wetness,and pressure of the air at different heights.Weather experts use the information to tell what the weather will be like in the future.
America's space agency uses rockets to launch weather balloons forty-thousand to sixty thousand meters up into the atmosphere.Radar follows the balloons to learn the speed and direction of high-altitude winds.The space agency also uses balloons to collect small meteorites,and to study the stars and planets.
People have flown very high into the atmosphere in balloons.These high flights began in the 1930s with Swiss physicist August Piccard.Piccard invented a cabin that did not let in,or let out,any air.In it,he flew safely as high as seventeen thousand meters to study radiation from space.
In the 1960s,soldiers jumped from balloons that were more than thirty thousand meters high.Their job was to test special air pressure clothing and new kinds of parachutes.
For years,balloonists tried and failed to cross the oceans.Then in 1978,three Americans made the first balloon flight across the Atlantic Ocean.The first balloon flight across the Pacific Ocean took place three years later.
Balloons have proved their value for science.But they also have proved to be fun.
People in many countries join balloon clubs.They take part in races and other competitions.The goal of some competitions is to see whose balloon can remain in the air the longest or travel the farthest.Sometimes,the goal is to land at a marked place within a fixed period of time.
World champion races for hot-air balloons or gas-filled balloons take place every year in different countries.
One international competition begins in Switzerland.Brightly-colored balloons sail through the sky over the white tops of the snow-covered Alps Mountains.Another competition begins in Albuquerque,New Mexico.There,balloons sail over the high desert of America's southwest.
People enjoy the feeling of floating gently over the countryside.Balloonists have discovered a way to see the Earth as birds must see it moving slowly and silently below them.
这是原文
Balloonists have discovered a way to see the Earth as birds must see it moving slowly and silently below them.
主要是翻译这一句,尤其是must、it、them这3个次到底怎么翻译,到底是只什么,顺便把这个句子也翻翻吧,
这是原文
Ballooning-(III)
Today,balloons play a very important part in scientific research.
Balloons carry heavy scientific instruments up to the edge of Earth's atmosphere.The instruments measure the temperature,wetness,and pressure of the air at different heights.Weather experts use the information to tell what the weather will be like in the future.
America's space agency uses rockets to launch weather balloons forty-thousand to sixty thousand meters up into the atmosphere.Radar follows the balloons to learn the speed and direction of high-altitude winds.The space agency also uses balloons to collect small meteorites,and to study the stars and planets.
People have flown very high into the atmosphere in balloons.These high flights began in the 1930s with Swiss physicist August Piccard.Piccard invented a cabin that did not let in,or let out,any air.In it,he flew safely as high as seventeen thousand meters to study radiation from space.
In the 1960s,soldiers jumped from balloons that were more than thirty thousand meters high.Their job was to test special air pressure clothing and new kinds of parachutes.
For years,balloonists tried and failed to cross the oceans.Then in 1978,three Americans made the first balloon flight across the Atlantic Ocean.The first balloon flight across the Pacific Ocean took place three years later.
Balloons have proved their value for science.But they also have proved to be fun.
People in many countries join balloon clubs.They take part in races and other competitions.The goal of some competitions is to see whose balloon can remain in the air the longest or travel the farthest.Sometimes,the goal is to land at a marked place within a fixed period of time.
World champion races for hot-air balloons or gas-filled balloons take place every year in different countries.
One international competition begins in Switzerland.Brightly-colored balloons sail through the sky over the white tops of the snow-covered Alps Mountains.Another competition begins in Albuquerque,New Mexico.There,balloons sail over the high desert of America's southwest.
People enjoy the feeling of floating gently over the countryside.Balloonists have discovered a way to see the Earth as birds must see it moving slowly and silently below them.
这是原文
Balloonists have discovered a way to see the Earth as birds must see it moving slowly and silently below them.
主要是翻译这一句,尤其是must、it、them这3个次到底怎么翻译,到底是只什么,顺便把这个句子也翻翻吧,
问题解答：
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