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  3. If our solar system has a Hell, it’s Venus. The air is choked with foul and corrosive sulfur, heaved from ancient volcanoes and

If our solar system has a Hell, it’s Venus. The air is choked with foul and corrosive sulfur, heaved from ancient volcanoes and

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问题     If our solar system has a Hell, it’s Venus. The air is choked with foul and corrosive sulfur, heaved from ancient volcanoes and feeding acid clouds above. Although the second planet is a step farther from the sun than Mercury, a runaway greenhouse effect makes it hotter indeed. It’s the hottest of the nine plants, a toasty 900 degrees Fahrenheit of baking rocky flats from equator to poles. All this under a crushing atmospheric pressure 90 times that of where you’re sitting now. From the earthly perspective, a dead end. It must be lifeless.
    "Venus has nothing," is the blunt word from planetologist Kevin Zahnle of NASA Ames Research Center in California’s Silicon Valley. "We’ve written it off."
    Yet a small group of advanced life-forms on Earth begs to differ, and theorizes that bizarre microbial ecosystems might have once populated Venus and, in fact, may be there still. Members of this loose band of researchers suggest that their colleagues have water too much on the brain, and are, in a sense, H2O chauvinists.
    "Astrobiologists are neglecting Venus due more to narrow thinking than actual knowledge of the environment, or environments, where life can thrive," says Dirk Schulze-Makuch, a geobiologist at the University of Texas at El Paso who recently co-authored a Venus-boosting paper in Astrobiology with colleague Louis Irwin.
    The bias against life on Venus is partly rooted in our own biology. Human experience instructs that liquid water, preferably lot of it, is essential for life. In search for extraterrestrial life, we obsess over small rivers in Mars’ surface apparently carved by ancient gushes of water, and delight in hints of permafrost just underneath its surface.(By comparison, Venus isn’t even that interesting to look at: A boring cue ball for backyard astronomers, its clouds reflects 75% of visible light.)Attention and then funding follow the water: Three more landers will depart for Mars this spring, and serious plans for sample-return missions hover in the midterm future.
    "If you have limited resources, you base exploration on what you know," says Arizona State University planetary geologist Ronal Greeley. It’s like losing your keys on the way home at night: The first place you look is under the streetlights not because they’re more likely to be there, but because if they are, you’ll spot them. For astrobiologists, the streetlights are the spectral lines for water, and they’ve spotted that potential on Mars, Jupiter’s moon Europa, even Neptune’s moon Triton. Not on the baking rocky flats of Venus.
Venus is the hottest of all the nine planets in the solar system because
选项 A、it is not so close to the Sun as Mercury.
B、many volcanoes spread the whole planet.
C、it is covered by a thick layer of cloud.
D、greenhouse effect is uncontrollable on it.
答案D
解析 从第1段第3、4句所述可以推断，金星比其他行星都热，是因为温室效应肆虐(runaway)，因此正确答案应为D。A关于金星离太阳的距离，B关于金星上的火山，C关于覆盖金星的云层，都在同一段中提到，虽然按照常理，这些因素都可能使某个地方的温度上升，但文中没有说明它们是导致金星温度比别的行星高的原因，因此，回答问题时一定要紧扣文章。
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