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 bum 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(恒星質(zhì)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 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 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 (軌道) do not change because the newly formed black hole contains exactly the same amount of mass as when it was a star, only this 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 not possible to detect black holes via a telescope. But astronomers continue to explore galaxies (銀河系) , space and the solar system to understand how black holes. It is possible that black holes can exist for millions of years, and later contribute further 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.
23"～26概括大意
23. Paragraph 1 __________
24. Paragraph 2 __________
25. Paragraph 3 __________
26. Paragraph 4 __________
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?.
27～30完成句子
27. Black holes are formed after__________.
28. When a large star explodes, the gravity compacts ever 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
23.C。第一段沒(méi)有主題句，通過(guò)第二句可知黑洞形成是由于巨大的星體爆炸，第三旬說(shuō)明了巨大的星體是如何爆炸的，所以第一段講的就是黑洞的形成過(guò)程，因此答案為C(黑洞是如何形成的)。
24.F。第二段首句是主題句，即“黑洞來(lái)自于那些由氫、其他氣體以及一些金屬組成的星體”，因而F選項(xiàng)(黑洞是由什么構(gòu)成的)為正確答案。
25.E。第三段的主題句為首句，即“被黑洞吞噬的物體永遠(yuǎn)存在，永遠(yuǎn)不會(huì)逃逸出來(lái)”。但第二個(gè)句子是將but放在句首，所以重點(diǎn)就轉(zhuǎn)向第二個(gè)句子，即“但是要記住黑洞只能吞噬與其保持特定距離的物體”，所以E(黑洞周?chē)奈矬w會(huì)怎么樣)為正確答案。
26.A。第四段的主題句是首句，即“到目前為止，天文學(xué)家根據(jù)愛(ài)因斯坦的相對(duì)論已經(jīng)推斷出黑洞的存在”，后面的句子都是有關(guān)天文學(xué)家對(duì)黑洞的研究，并且證明黑洞是真實(shí)存在的，所以A選項(xiàng)(有證據(jù)證明黑洞真實(shí)存在嗎)為正確答案。
27.B。題干：黑洞是在__________之后形成的。利用題干的關(guān)鍵詞black holes和form可以定位到第一段第二句，可知科學(xué)家發(fā)現(xiàn)黑洞源于巨大的星體爆炸，所以正確答案為B(巨大星體的爆炸)。
28.C。題干：當(dāng)巨大的星體爆炸時(shí)，重力將爆炸物壓縮成__________。利用題干的關(guān)鍵詞explode，compact，gravity可以定位到第二段：“…，and the gravity starts to compact every piece into the tiniest particle.”可知重力把爆炸產(chǎn)生的物體壓縮成顆粒。因此此處填“最微小的粒子”，所以正確答案為C(最微小的顆粒)。
29.D。題干：新形成的黑洞和產(chǎn)生黑洞的那個(gè)星體__________。利用題干關(guān)鍵詞the newly formed black hole可以定位到文章第三段“the newly formed black hole contains exactly the same amount ofmass as when it was a star”，可知黑洞和形成黑洞的那個(gè)星體的質(zhì)量相同，所以正確答案為D。
30.E。題干：愛(ài)因斯坦的相對(duì)論有助于證明__________。利用題干關(guān)鍵詞Albert Einstein’s theory定位到文章第四段第一句，可知天文學(xué)家斷定黑洞的存在是因?yàn)閻?ài)因斯坦的相對(duì)論，所以正確答案為E。