《2025年高中必刷题高一英语必修第三册人教版》

B
语篇类型:说明文 主题:寻找类地行星 词数:334 难度:偏难 建议用时:8分钟
[福建福州九校2025高一期末联考]With the fast development of astronomy, astronomers are eager to find a clue of the familiar: planets that are like Earth. By pushing technology to the limit, astronomers are rapidly approaching the day when they can find another Earth.
The most direct approach is to take a picture of it with a telescope. However, a more effective way is to use “the Doppler technique”. This involves analysing starlight for evidence that the moving position of the star is affected by the gravity of a planet. Nowadays, astronomers can tell when a planet is pulling its star from its appointed rounds by only one metre a second—about human walking speed. That's enough to detect a giant planet in a big orbit, or a small planet if it's close to its star.
Another approach is to watch a star for a slight drop in its brightness. This occurs when an orbiting planet passes in front of the star and blocks part of its light. At most a tenth of all planetary systems are likely to be oriented so that these mini-eclipses (迷你日食)—called transits (凌日)—are visible from Earth. So, astronomers must monitor a lot of stars to catch just a few transits.
The dream of astronomers is to discover a rocky planet roughly the size of Earth orbiting in a habitable zone, one that is neither too hot nor too cold to support life. If they succeed, they will have found what biologists believe could be a promising residence for life.
The best places to look for Earth-like planets may be dwarf stars. Smaller than the sun, dwarf stars are plentiful; seven of the ten stars nearest to Earth are dwarf stars. They also provide a steady supply of sunlight to any life-bearing planets within their habitable zone. Additionally, dwarf stars are dim (暗淡的), so the habitable zone lies closer in. If the planet is closer to the star, it's easier for astronomers to observe a transit. A close-in planet also has a stronger pull on its star. That makes it easier to detect the planet with the Doppler method.
1. What do astronomers aim to discover by analysing starlight according to paragraph 2?
A. Where a giant orbit can be detected.
B. Why a small planet is close to its star.
C. How strong the power of the gravity is.
D. Whether the movement of the star is changed.
2. Why do astronomers have to monitor a lot of stars to capture transits?
A. Most planetary systems don't have transits.
B. Transits only occur for a small number of stars.
C. Transits of planetary systems last a very short period.
D. At most 10% of planetary systems have visible transits.
3. Why are dwarf stars ideal for spotting Earth-like planets?
A. They are limited in number.
B. Their planets are close to the Earth.
C. Closer habitable zones help detection.
D. The brightness improves their visibility.
4. What is the main purpose of the text?
A. To describe planet-finding processes.
B. To promote space tools used to find habitable planets.
C. To argue human beings can soon find habitable planets.
D. To inform readers of methods of finding Earth-like planets.

答案： 【语篇导读】本文是一篇说明文。文章主要介绍了天文学家寻找类地行星的方法和目标，他们使用望远镜、多普勒技术和监测恒星亮度变化等方法来寻找类地行星。
1.D 细节理解题。根据第二段中的“However, a more effective way is to use ‘the Doppler technique’. This involves analysing starlight for evidence that the moving position of the star is affected by the gravity of a planet.”可知，科学家利用多普勒技术来分析星光，目的是发现恒星的运动是否会受到某个行星引力的影响而发生改变。故选 D 项。
2.D 细节理解题。根据第三段中的“At most a tenth of all planetary systems are likely to be oriented so that these mini-eclipses—called transits—are visible from Earth. So, astronomers ♦黑板：此处 So 提示了前后句之间的因果关系。
must monitor a lot of stars to catch just a few transits.”可知，天文学家必须监测很多恒星才能捕捉到一些凌日现象，是因为从地球上能够观测到凌日现象的行星系不超过 10%。
3.C 推理判断题。根据最后一段中的“Additionally, dwarf stars are dim, so the habitable zone lies closer in. If the planet is closer to the star, it’s easier for astronomers to observe a transit. A close-in planet also has a stronger pull on its star. That makes it easier to detect the planet with the Doppler method.”可知，矮星亮度不高，故其宜居带距离近。宜居带内的行星若离矮星更近，天文学家就更容易观测到其凌日现象，这样就更容易发现类地行星的存在。因此，矮星更近的宜居带提高了发现类地行星的可能性。故选 C 项。
4.D 推理判断题。根据第一段内容并结合全文内容可知，文章主要介绍了天文学家寻找类地行星的方法和目标，他们使用望远镜、多普勒技术和监测恒星亮度变化等方法来寻找类地行星。由此推断，这篇文章的主要目的是向读者介绍寻找类地行星的方法。故选 D 项。