题型:阅读理解 题类:常考题 难易度:普通
北京市朝阳区2019届高三上学期英语期末考试试卷
Why Mars (火星) is New Settlement
Is it possible to live on other planets? The United States government is taking a serious look at the moon and Mars as potential places for future human settlement. The moon could serve as a training ground for later journeys to Mars. Currently, with Mars becoming the eventual long-term goal, serious questions exist as to whether the dangers of the settlement on the moon are too extreme and unnecessary.
One major reason the settlement on the moon is too dangerous is the difference between the atmosphere environment of the moon and Mars. Atmosphere is important because it protects humans and all other life from a continuous attack of radiation (辐射) caused by sources such as the sun. This radiation is especially dangerous to humans because it increases the risk of cancer and can negatively change DNA. The fact that the moon has no atmosphere can cause great harm to human beings. Although Mars' atmosphere is significantly thinner than Earth's, at least it has one and would create some sort of protective barrier for humans.
Another important characteristic necessary for human settlement is natural resources like water, of which the moon is believed to have none. Mars, however, contains vast quantities of water ice, dry ice, and also snow. There is also sufficient evidence that water once existed at the surface of Mars and might return in the future if the planet warms. With increased technologies, the potential for settlers to remain on Mars by being increasingly self-sufficient makes Mars a much more attractive goal as the space settlement than the moon.
Future settlers will not only benefit from potential water on Mars; the planet is also rich in other natural resources such as oxygen, hydrogen, and minerals, which can be well used in productive ways. For example, hydrogen can be used as fuel, and it can be combined with nitrogen (氮气) to form new materials necessary for human settlement. Due to these advantages,
Mars would be a more successful planet for exploration and settlement because it contains the basic resources necessary for humans to survive.
Since the environment of Mars is more similar to that of Earth and it contains resources necessary to help life exist, it should be the only option for any kind of long-term human settlement. The settlement on Mars would not only be a milestone in space but also an excellent chance for mankind to improve itself from past adventures on Earth and preserve and make the best use of the natural resources Mars has to offer.
CP: Central Point P: Point Sp: Sub-point (次要点) C: Conclusion
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