单项选择题

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 Veuns 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 (盲目的爱国者).
"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 (永久冻结带) just underneath its surface. (By comparison, Venus isn’t even that interesting to look at: A boring cue ball (台球的白色母球) 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 (光谱的) 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.
It can be inferred from the passage that the small group of advanced life-forms on Earth believed that ______.

A.life could exist in hot environment
B.life could exist without water
C.there are still lives on Venus

D.there used to be lives on Mars
热门 试题

单项选择题
Pointcast Network is most probably ______. A.a company that develops the latest push software B.a tool that promotes a company’s online marketing C.the first company that used an online push software D.the most popular software that helps a company push
Another major shift in the model for Internet commerce concerns the technology available for marketing. Until recently, Internet marketing activities have focused on strategies to "pull" customers into sites. In the past year, however, software companies have developed tools that allow companies to "push" information directly out to consumers, transmitting marketing messages directly to targeted customers. Most notably, the Pointcast Network uses a screen saver to deliver a continually updated stream of news and advertisements to subscribers’ computer monitors. Subscribers can customize the information they want to receive and proceed directly to a company’s Web site. Companies such as Virtual Vineyards are already starting to use similar technologies to push messages to customers about special sales, product offering, or other events. But push technology has earned the contempt of many Web users. Online culture thinks highly of the notion that the information flowing onto the screen comes there by specific request. Once commercial promotion begins to fill the screen uninvited, the distinction between the Web and television fades. That’s a prospect that horrifies Net purists.But it is hardly inevitable that companies on the Web will need to resort to push strategies to make money. The examples of Virtual Vineyards, Amazon.com, and other pioneers show that a Web site selling the right kind of products with the right mix of interactivity, hospitality, and security will attract online customers. And the cost of computing power continues to free fall, which is a good sign for any enterprise setting up shop in silicon. People looking back 5 or 10 years from now may well wonder why so few companies took the online plunge.
填空题
D