《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:火星上发现菱铁矿 词数:337 难度:偏难 建议用时:8分钟
[广东深圳 2025 期末] The Curiosity rover (探测器) has found strong evidence that ancient Mars once had a carbon cycle—a process crucial for sustaining life. While examining rocks in Mars' Gale Crater, the rover discovered siderite—a special mineral that forms when carbon mixes with iron. This suggests Mars' environment long ago was similar to the early Earth's. The discovery, published in the journal Science in April 2025, makes scientists hopeful that future Martian samples might show signs of past life.
Lead researcher Benjamin Tutolo from the University of Calgary described the excitement about the discovery: "When we realised these rocks contained so much siderite, I knew its significance immediately. " For the Earth, the carbon cycle has been key to its habitability—cycling carbon between the air, the ocean, and rocks, thus providing the key material for all living things and creating the suitable atmosphere. Mars, despite signs of ancient water, has never shown evidence of carbonates until now. Finding rocks with 5%—10% siderite means Mars had a hidden carbon source we didn't know about.
Since landing in 2012, Curiosity has been exploring Gale Crater, drilling into rocks and analysing them. Recent tests found not just siderite but also magnesium sulfate salts (硫酸镁盐), which may have hidden the carbonates from satellites. Tutolo thought similar minerals could exist all over Mars, possibly storing much of the planet's lost CO₂—a gas that once kept Mars warm.
However, Mars' carbon cycle appears to have been unstable. Unlike the Earth, Mars has no plate tectonics (板块运动) to recycle carbon. Instead, acidic water (pH＜7) may have trapped CO₂ in rocks, causing the atmosphere to slowly disappear. Over time, this has turned Mars into the cold and dry desert we see today—right around the same period when life first emerged on Earth.
Although the mission to bring Martian samples back to Earth is delayed, Curiosity keeps studying the planet's rocks. The discovery of siderite helps explain Mars' unique carbon cycle, which weakens as the planet cools. While it's still unclear whether this prevents the emergence of life, the findings provide critical insights into Mars' history.
1. What is the significance of the discovery of siderite on Mars?
A. It proves Mars once had liquid water.
B. It helps explore Mars' volcanic history.
C. It suggests Mars once could support life.
D. It shows how minerals on Mars formed.
2. What does the discovery of magnesium sulfate salts explain?
A. Why carbonates escaped detection.
B. Where potential life might emerge.
C. How water disappeared from Mars.
D. When the red planet became warm.
3. Why was Mars unable to maintain its carbon cycle stably?
A. It trapped too much water.
B. Its temperature was unstable.
C. Its atmosphere was too thick.
D. It lacked earth-like plate tectonics.
4. What is a suitable title for the text?
A. The Red Planet's Change Into Desert
B. The Ongoing Climate Change of Mars
C. The Curiosity Rover's New Technical Breakthrough
D. From the Hidden Carbon Cycle to Mars' Past

答案： 【语篇导读】本文是一篇说明文。文章主要介绍了“好奇号”探测器在火星上发现了菱铁矿,这一发现揭示了火星上曾经存在碳循环,并说明了碳循环的意义、火星碳循环不稳定的原因以及这一发现的研究价值。
1.C 细节理解题。根据第一段中的“The Curiosity rover has found strong evidence that ancient Mars once had a carbon cycle—a process crucial for sustaining life.”及“The discovery... makes scientists hopeful that future Martian samples might show signs of past life.”可知,菱铁矿的发现表明火星上曾经存在碳循环,这是维持生命的关键过程,科学家们对未来的火星样本可能显示出过去的生命迹象满怀希望,因此,这一发现的意义是它暗示火星可能曾经有生命存在。故选C项。
2.A 细节理解题。根据第三段中的“Recent tests found not just siderite but also magnesium sulfate salts, which may have hidden the carbonates from satellites.”可知,硫酸镁盐的发现解释了为什么碳酸盐没有被卫星探测到。故选A项。
3.D 细节理解题。根据第四段中的“However, Mars’ carbon cycle appears to have been unstable. Unlike the Earth, Mars has no plate tectonics to recycle carbon.”可知,火星无法稳固地维持其碳循环是因为它缺乏像地球那样的板块运动。
4.D 主旨大意题。通读全文可知,文章开篇点明“好奇号”探测器在火星上发现了菱铁矿,这一发现揭示了火星过去存在碳循环,为火星可能曾存在生命提供了重要线索,紧接着下文介绍了碳循环的意义和火星碳循环不稳定的原因,最后强调了这一发现的研究价值,指出其为研究火星的历史提供了重要见解。因此,D项(从隐藏的碳循环到火星的过去)符合文章主旨,适合作为本文的标题。故选D项。