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  3. The U. S. space agency, NASA, is planning to launch a satellite that scientists hope will answer fundamental questions about the

The U. S. space agency, NASA, is planning to launch a satellite that scientists hope will answer fundamental questions about the

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问题     The U. S. space agency, NASA, is planning to launch a satellite that scientists hope will answer fundamental questions about the origin and destiny of our universe. (1)______
    The prevailing theory of the universe’s origin, the "Big Bang" theory, says all matter and energy were once compressed into a tiny point. The density and resulting temperature were so enormous that, about 13-to-15-billion years ago by current estimates, a mighty explosion flung the matter hurtling outward in all directions. (2) ______They also ask, is the expansion accelerating? Will the universe collapse? What is its shape? Scientists will seek explanations with NASA’s new Microwave Anisotropy Probe, abbreviated as MAP. (3)______
    "MAP will take the ultimate baby picture, an image of the infant universe taken in the fossil light that is still present from the Big Bang, " he says. "This glow, this radiation, is the oldest light in the universe. Imprinted on this background, physicists knew, would be the secrets of the Big Bang itself. "
    This background radiation is the light and heat that the early cosmic soup of matter emitted. Once roiling hot, it has cooled over the eons to just a few degrees above absolute zero. It was once thought to be distributed evenly. But in 1992, a highly sensitive NASA satellite named COBE detected nearly imperceptible variations in temperature as tiny as 30-millionths of a degree.
     (4)______"These patterns result from tiny concentrations that were in the very early universe that were the seeds that grew to become the stars and the galaxies that we see today, " he says. "The tiny patterns in the light hold the keys for understanding the history, the content, the shape, and the ultimate fate of our universe."
     (5)______Princeton University scientist David Spergel says MAP will give us a much more accurate matter count than we have now. "Right now, we want to measure something like the matter-density of the universe, " he says. "Today, we can estimate that to a factor of two. That’s pretty good. What we want to do is be able to measure it to about the three-percent level, which is what MAP will be capable of doing."
    To do its job, the $ 145 million MAP spacecraft will settle into an orbit 1.5 million kilometers from the Earth. This is where the Earth’s and sun’s gravitational pull are equal, and well past the range of the Earth’s own obscuring microwave radiation.
    While the older COBE satellite measured just a small part of the sky, Charles Bennett says MAP will scan the entire sky at 1, 000 times better resolution. "The patterns that MAP measures are extremely difficult to measure, " he says. "MAP will be measuring millionths of a degree temperature accuracies, and that’s hard to do. That’s like measuring the difference between two cups of sand to the accuracy of a single grain of sand. "
[A] The principal NASA scientist for the new MAP spacecraft, Charles Bennett, says the heat patterns represent slight differences in the density of the young universe, where denser regions evolved into the present web of structures.
[B] NASA says the first results from the MAP mission will be ready in about 18 months after launch.
[C] The spacecraft will orbit the Earth seeking answers from an extremely faint glow of microwaves that have existed since the beginning of time.
[D] Scientists are trying to learn how it clumped together to produce stars, clusters of stars called galaxies, and clusters of galaxies.
[E] Astronomers are reporting evidence that points to a massive star-eating black hole at the center of our Milky Way galaxy.
[F] One of those keys is the amount of matter and its density. More matter with a higher density means more gravitational pull, suggesting a slowing of the universe’s expansion, and perhaps even its collapse.
[G] The head of NASA’s Evolution of the Universe program, Alan Bunner, says MAP will measure what is thought a remnant of the Big Bang—an afterglow of microwaves bathing the universe that was emitted by the ancient cosmic matter.
选项
答案F
解析 空白处的前一段谈论光波模式如何如何，而空白处以下讨论的是“MAP”为物质密度的测量提供了更先进手段，明照中间需要有所过渡，F项中“One of those keys”正与上一句“…hold the keys for understanding…”呼应，而“the amount of matter and its density”止与下面讨沦的内容相衔接．因此很好地完成了过渡的作用。本题的空白处位于文章的第六段。前面的一段谈到，宇宙中残留的原始物质发出的光波模式中蕴含了了解宇宙历史、构成成分、形状和最终的命运的关键信息。第六段接着谈到“MAP”将为我们提供有关物质密度更为详尽的信息。由此看来B项和F项都是可能的选项。B项提到在卫星发射18个月后可以得到“MAP”探测的数据，而F项谈及的是宇宙物质密度可能带来的科学启示。根据与上下文结合的有机程度，可以判断F项优于B项，故本题的正确选项为F项。
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