[originaltext] Since the beginning of history, people on the earth have alwa

游客2024-02-19  17

问题  
Since the beginning of history, people on the earth have always watched the sky and wondered about the things they saw. As centuries of discoveries flew by, it became obvious that humans would not be content to just gaze at the solar system. We wanted to fly into it and explore it as well.
    Once again, technology allowed us to accomplish our goal. (33)On October 4, 1957. a Soviet rocket sent the first man-made satellite into space. It was called Sputnik, the Russian word for "traveler". Even though Sputnik was nothing more than a small aluminum ball with a radio inside, it started a whole new era of space exploration.
    In May 1961 President John F. Kennedy challenged American scientists to land a person on the moon before the end of the 1960s. (34)In the quest to do this, scientists faced many obstacles. For example, to get a spaceship all the way to the moon and back would demand a rocket engine powerful enough to make the trip. (35)Scientists realized that it would be difficult for one heavy rocket loaded with fuel to reach the moon. Instead, they decided to use a multistage rocket. When the fuel in one stage of the multistage rocket is used up, that stage will fall away. This makes the rocket lighter, and the engine of the next stage can go on providing power and thrust the rocket even faster and higher. As you know, Americans successfully landed on the moon in July 1969. Since then our knowledge of the solar system has increased dramatically.

选项 A、How to make a powerful rocket engine.
B、How to ensure the safety of the crew.
C、How to choose qualified crewmen for the trip.
D、How to enable the spacecraft break free of gravity.

答案 A

解析 听力中提到,准备登月行动行动时,科学家们面临许多障碍,其中最关键的问题是a rocket engine powerful enough to make the trip,即一个动力足够强大的能够完成旅程的火箭推进器,所以本题的正确答案为A。
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