共用题干 第一篇An Expensive MistakeIs there water on the planet Mars? Is there life...

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问题 共用题干
第一篇

An Expensive Mistake

Is there water on the planet Mars? Is there life on Mars?Was there ever life on Mars?Scientists from
NASA wanted to know the answers to tliese questions.They built a spacecraft to travel around Mars and get
informnation.The spacecraft was called the Mars Climate orbiter.
The Mars Climate Orbiter left for Mars iii December 1998.The trip took nine and a half months.At first,
everything was fine.However.when the Orbiter got near Mars,something terrible happened.The spacecraft
didn't go to the right place.It went too close to Mars.it was too hot for the Orbiter there.The spacecraft
couldn't function correctly.Suddenly,it stopped sending messages to NASA.The Orbiter was lost.
How could this terrible thing happen? How did the Orbiter get closer to Mars than the scientists
planned? Finally,they found the anlswer. Two teams of scientists worked together on the Orbiter. One team
was in England,and one teann was in the United States.There were many similarities in the way they
worked,but there was one important difference:The teams used different guidelines for measuring things.The
United States team used the metric systcnni(公制).The oilier team used the English system.
Because they used different systems,the scientists made a mathematical mistake.The Orbiter's orbit
(the shape and pattern of its path)around Mars was not correct.The scientists put the Orbiter on the wrong
path.The Orbiter got too close amid too hot,and it stopped functioning.

Why didn'tanybody see the mistake before it was too late?Many things contributed to the problem.
One thing was that NASA scientists and mathematicians were working on two other spacecrafts at the same
time.This was a challenge,and they were very tired from working long hours.
The Mars Climate Orbiter cost $94 million to build.It also cost a lot of money to try to find the lost Or-
biter in space.In addition,NASA's research on the cause of the problem was very expensive.This wasn't
the first time that two different measurement systems caused mistakes in scientific projects.However,the
Mars Climate Orbiter was definitely the most expensive mistake of all!

选项 Why didn't NASA scientists identify the problem before the Orbiter left for Mars?
A:They didn'tknow the English system.
B:They were sure of the success of the trip.
C:They were tired from working long hours.
D:They didn'tget enough research funding.

答案C

解析文章第一段以三个问句开头:“火星上有水吗?"“火星上有生命吗?"“火星上有过生命吗?”接着指出NASA的科学家们想知道这些问题的答案,他们建造了航天飞船环绕火星飞行来获得信息。故选B。
由文章第二段第二句话可知,飞船从地球到火星的旅程花费了九个半月的时间,故选B。
由文章第二段第三、四句话“Atfirst,everythingwasfine.However,whentheOrbitergotnearMars,somethingterriblehappened.”可知飞船是在接近火星时出现问题的。
由文章第三段和第四段可知,来自英国和美国的两组科学家共同负责飞船的工作,他们在做计算工作时采用了不同的计算准则。这造成计算数据出错,导致飞船绕火星飞行的轨道出现偏差。故选D。
由文章倒数第二段可知,科学家们没能发现错误的其中一个原因是NASA的科学家和数学家们同时还要负责另外两个航天器的工作,长时间的工作使他们非常疲惫。故选C。
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