第3部分：概括大意与完成句子（第23-30题，每题1分，共8分)
下面的短文后有2项测试任务：（1)第23~26题要求从所给的6个选项中为指定段落每段选择1个最佳标题；（2)第27~30题要求从所给的6个选项中为每个句子确定一个最佳选项。
Black Holes
1. Black holes can be best described as a sort of vacuum, sucking up everything in space. Scientists have discovered that black holes come from an explosion of huge stars. Stars that are near death can no longer burn due to loss of fuel, and because its temperature can no longer control the gravitational (重力的) force, hydrogen ends up putting pressure onto the star’s surface until it suddenly explodes then collapses.
2. Black holes come from stars that are made of hydrogen, other gases and a few metals. When these explode it can turn into a stellar-mass (恒星质量) black hole, which can only occur if the star is large enough (should be bigger than the sun) for the explosion to break it into pieces, and the gravity starts to compact every piece into the tiniest particle. Try to see and compare: if a star that’s ten times the size of the sun ends up being a black hole that’s no longer than 70 kilometers, then the Earth would become a black hole that’s on
www.med126.comly a fraction of an inch!
3. Objects that get sucked in a black hole will always remain there, never to break free. But remember that black holes can only gobble up (吞噬) objects within a specific distance to it. It’s possible for a large star near the sun to become a black hole, but the sun will continue to stay in place. Orbits do not change because the newly formed black hole contains exactly the same amount of mass as when it was a star, only this time its mass is totally contracted that it can end up as no bigger than a state.
4. So far, astronomers have figured out that black holes exist because of Albert Einstein’s theory of relativity. In the end, through numerous studies, they have discovered that black holes truly exist. Since black holes trap light and do not give off light, it is nearly impossible to detect black holes via a telescope. But astronomers continue to study galaxies, space and the solar system to understand how black holes might evolve. It is possible that black holes can exist for millions of years, and later contribute to a bigger process in galaxies, which can eventually lead to creation of new entities. Scientists also credit black holes as helpful in learning how galaxies began to form.
A. Is there proof that black holes really exist?
B. What are different types of black holes?
C. How are black holes formed?
D. How were black holes named?
E. What happens to the objects around a black hole?
F. What are black holes made of?
23. Paragraph 1
24. Paragraph 2
25. Paragraph 3
26. Paragraph 4
27. Black holes are formed after .
28. When a large star explodes, the gravity compacts every piece into .
29. A newly formed black hole and the star it comes from are of .
30. Albert Einstein’s theory of relativity helps to prove .
A. the creation of new entities
B. an explosion of huge stars
C. the tiniest particle
D. the same amount of mass
E. the existence of black holes
F. a fraction of an inch
第4部分：阅读理解（第31-45题，每题3分，共45分)
下面有3篇短文，每篇短文后有5道题。请根据短文内容，为每题确定1个最佳选项。
第一篇Energy and Public Lands
The United States boasts substantial energy resources. Federal lands provide a good deal of U.S. energy production; the U.S. Department of the Interior manages federal energy leasing, both on land and on the offshore Outer Continental Shelf. Production from these sources amounts to nearly 30 percent of total annual U.S. energy production.
In 2000, 32 percent of U.S. oil, 35 percent of natural gas, and 37 percent of coal were produced from federal lands, representing 20,000 producing oil and gas leases and 135 producing coal leases. Federal lands are also estimated to contain approximately 68 percent of all undiscovered U.S. oil rese
www.med126.comrves and 74 percent of undiscovered natural gas.
Revenues from federal oil, gas, and coal leasing provide significant returns to U.S. taxpayers as well as State governments. In 1999, for example, $553 million in oil and gas revenues were paid to the U.S. Treasury, and non-Indian coal leases accounted for over $304 million in revenues, of which 50 percent were paid to State governments. Public lands also play a critical role in energy delivery. Each year, federal land managers authorize rights of way for transmission lines, rail systems, pipelines, and other facilities related to energy production and use.
Alternative energy production from federal lands lags behind conventional energy production, though the amount is still significant. For example, federal geothermal resources produce about 7.5 billion kilowatt-hours of electricity per year, 47 percent of all electricity generated from U.S. geothermal energy. There are 2,960 wind turbines on public lands in California alone, producing electricity for about 300,000 people. Federal hydropower facilities produce about 17 percent of all hydropower produced in the United States.
Because of the growing U.S. thirst for energy and increasing public unease with dependence on foreign oil sources, pressure on the public lands to meet U.S. energy demands is intensifying. Public lands are available for energy development only after they have been evaluated through the land use planning process. If development of energy resources conflicts with management or use of other resources, development restrictions or impact mitigation measures may be imposed, or mineral production may be banned altogether.
31. What is the main idea of this passage?
A. Public lands are one of the main sources of revenues.
B. Public lands play an important role in energy production.
C. Public lands should be developed to ease energy shortage.
D. Public lands store huge energy resources for further development.
32. Which of the following statements is true of public lands in the U.S.?
A. The majority of undiscovered natural gas is stored there.
B. Half of U.S. energy is produced there.
C. Most of coal was produced from there in 2000.
D. Most energy resources are reserved there.
33. Geothermal resources, wind turbines, and hydropower facilities in Paragraph 4 are cited as examples to illustrate that
A. the amount of alternative energy production from public lands is huge.
B. alternative energy production is no less than conventional energy production.
C. they are the most typical conventional energy resources from public lands.
D. geothermal resources are more important than the other two.
34. There is a mounting pressure on public lands to satisfy US energy demands because
A. the US is demanding more and more energy
www.med126.com.
B. many Americans are unhappy with energy development in foreign countries.
C. quite a few public lands are banned for energy development.
D. many Americans think public lands are being abused.
35. Public lands can be used for energy development when
A. energy development restrictions are effective.
B. federal land managers grant permissions.
C. they go through the land use planning process.
D. there is enough federal budget.
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