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[共享题干题]【2013年真题】  （一） Black Hole  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 thatare near death can no longer burn due to loss of fuel, and because its temperature can nolonger control the gravitational ( 重力的) force, hydrogen ends up putting pressure onto thestar'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. Whenthese explode it can turn into a stellar-mass (恒星质量) black hole, which can only occurif the star is large enough (should be bigger than the sun) for the explosion to break it intopieces, and the gravity starts to compact every piece into the tiniest particle. Try to see andcompare: if a star that's ten times the size of the sun end up being a black hole that's no longer than 70 kilometers, then the Earth would become black hole that's only a fraction ofan inch !   3.Objects that get sucked in a black hole will always remain there, never to break free. Butremember that black holes can only gobble up (吞噬) objects within a specific distance toit. It's possible for a large star near the sun to become a black hole, but the sun willcontinue to stay in place. Orbits (轨道) do not change because the newly formed blackhole contains exactly the same amount of mass as when it was a star, only this mass istotally 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'stheory of relativity. In the end, through numerous studies, they have discovered that blackholes truly exist. Since black holes trap light and do not give off light, it is not possible todetect black holes via a telescope. But astronomers continue to explore galaxies (银河系),space and the solar system to understand how black holes work. It is possible that black holescan exist for millions of years, and later contribute further process in galaxies, which caneventually lead to creation of new entities. Scientists also credit black holes as helpful inlearning how galaxies began to form.
单选题第1题Paragraph 3__________
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?

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