A
(2021·曲阜高二检测)
Salty water just below the surface of Mars could hold enough oxygen to support the kind of microbial (微生物的) life that existed and developed quickly on Earth billions of years ago, researchers reported on Monday.
In some locations, the amount of oxygen available could even keep alive a primitive, multicellular (多细胞的) animal such as a sponge (海绵动物), they reported in the journal Nature Geosciences. “We discovered that brines—water with high concentrations of salt—on Mars can contain enough oxygen for microbes to breathe, ” said lead author Vlada Stamenkovic, a theoretical physicist at the Jet Propulsion Laboratory in California. “This fully revolutionizes our understanding of the potential for life on Mars, today and in the past. ”
Up to now, it had been assumed that the trace (微量) amounts of oxygen on the Red Planet were insufficient to sustain even microbial life. “We never thought that oxygen could play a role for life on Mars due to its rarity in the atmosphere, about 0. 14 percent, ” Stamenkovic said. By comparison, the life-giving gas makes up 21 percent of the air we breathe.
On Earth, aerobic—that is, oxygen breathing—life-forms evolved (净化) together with photosynthesis (光合作用), which converts CO2 into O2. The gas played a critical role in the existence of complex life, known after the so-called Great Oxygenation Event some 2. 35 billion years ago.
But our planet also holds microbes—at the bottom of the ocean, in boiling hot springs—that live in environments lack of oxygen. “That’s why—whenever we thought of life on Mars—we studied the potential for anaerobic (无氧的)life, ” Stamenkovic said.
【文章大意】本文是一篇科教类阅读。文章主要讲述了研究人员周一报告称, 火星地表下的盐水可能含有足够的氧气, 支持数十亿年前在地球上快速生存和发展的微生物生命。
21. The underlined word “insufficient” in Para. 3 means “______”.
A. enough B. not enough
C. wrong D. right
【解析】选B。词义猜测题。 根据下文内容可知, “我们从来没有想过火星上的氧气会对生命产生作用, 因为它在大气中的含量只有0. 14%, ”斯塔门科维奇说。结合第三段第一句“到目前为止, 人们一直认为火星上微量的氧气不足以维持微生物的生命”, 所以“insufficient” 意为不充足的。故选B。
22. Vlada Stamenkovic may agree that ______.
A. this research changes people’s understanding of the potential for life on Mars
B. the life-giving gas makes up 31 percent of the air people breathe on earth
C. Great Oxygenation Event happened some 2. 35 million years ago
D. earth holds microbial life at the bottom of the desert
【解析】选A。推理判断题。根据第二段最后一句他说的话可知, Vlada Stamenkovic可能同意“这项研究改变了人们对火星生命潜力的理解”的观点。故选A。
23. The main idea of the passage is ______.
A. Mars is fit for living
B. multicellular animals are living on Mars
C. oxygen plays a role for life on earth
D. Mars is likely to have enough oxygen to support life
【解析】选D。主旨大意题。 根据第一段可知研究人员周一报告称, 火星地表下的盐水可能含有足够的氧气, 支持数十亿年前在地球上快速生存和发展的微生物生命。是全文的主题句, 结合全文内容, 可知这篇文章主要讲了火星可能有足够的氧气来维持生命。故选D。
【技巧点拨】
对关键词, 关键短语或者是关键句子的把握是解决推理判断题的重要方法之一, 它们往往隐藏着深层的意思。第22小题根据第三段 Up to now, it had been assumed that the trace amounts of oxygen on the Red Planet were insufficient to sustain even microbial life. “We never thought that oxygen could play a role for life on Mars due to its rarity in the atmosphere, about 0. 14 percent, ” Stamenkovic said. (到目前为止, 人们一直认为火星上的微量氧气不足以维持微生物的生命。斯塔门科维奇说: “我们从来没有想过火星上的氧气会对生命产生作用, 因为它在大气中含量很少, 只有0. 14%。”)可知, Vlada Stamenkovic可能同意“这项研究改变了人们对火星生命潜力的理解”的观点。故选A。
