首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
How many things can you see in the night sky? A lot! On a clear night you might see the Moon, some planets,and thousands of spar
How many things can you see in the night sky? A lot! On a clear night you might see the Moon, some planets,and thousands of spar
admin
2013-01-29
26
问题
How many things can you see in the night sky? A lot! On a clear night you might see the Moon, some planets,and thousands of sparkling stars.
You can see even more with a telescope. You might see stars where before you only saw dark space. You might see that many stars look larger than others. You might see that some stars that look white are really red or blue. With bigger and bigger telescopes you can see more and more objects in the sky. And you can see those objects in more and more details.
But scientists believe there are some things in the sky that we will never see. We won’t see them with the biggest telescope in the world, on the clearest night of the year. That’s because they’re invisible. They’re the mysterious dead stars called black holes.
You might find it hard to imagine that stars die. After all,our Sun is a star. Year after year we see it up in the sky burning brightly,giving us heat and light. The Sun certainly doesn’t seem to be getting old or weak. But stars do burn out and die after billions of years.
As a star’s gases burn,they give off light and heat. But when the gas runs out,the star stops burning and begins to die.
As the star cools,the outer layers of the star pull in toward the center. The star squashes into a smaller and smaller ball. If the star was very small, the star ends up as a cold, dark ball called a black dwarf. If the star was very big, it keeps squashing inward until it’s packed together tighter than anything in the universe.
Imagine if the each were crushed until it was the size of a tiny marble. That’s how tightly this dead star, a black hole is packed. What pulls the star in toward its center with such power? It’s the same force that pulls you down when you jump—the force called gravity. A black hole is so tightly packed that its gravity sucks in everything—even light. The light from black hole can never come back to your eyes. That’s why you see nothing but blackness.
So the next time you stare up at the night sky,remember: there’s more in the sky than meets the eyes! Scattered in the silent darkness are black holes—the great mystery of space.
What is the main idea of the article?
选项
A、The future of our Sun billions of years from now.
B、The difference between our Sun and a dead star.
C、The mystery of black holes in the universe.
D、The sparkling and dying stars in the sky.
答案
C
解析
题目问:文章的主要观点是什么?通过文章内容可知,文章主要是向读者在介绍黑洞的相关知识。包括黑洞是如何形成的,黑洞的特点等等。所以,答案是C。
转载请注明原文地址:https://jikaoti.com/ti/OoqYFFFM
0
考博英语
相关试题推荐
Mostpeoplewhotravellongdistancecomplainofjetlag.Jetlagmakesbusinesstravelerslessproductiveandmoreprone【21】makin
Appliedresearch,______tosolvespecificpracticalproblems,hasanimmediateattractivenessbecausetheresultscanbeseenand
Punditswhowanttosoundjudiciousarefondofwarmingagainstgeneralizing.Eachcountryisdifferent,theysay,andnoonest
Perhapsallcriminalsshouldberequiredtocarrycardswhichread:Fragile;HandlewithCare.Itwillneverso,thesedaystogo
Anynationthatinterferesintheinternalaffairsofanothernationshouldbe______condemned.
Thenovelcontainssomemarvellouslyrevealing______ofrurallifeinthe19thcentury.
Travellingandmeetingnewpeople______themindofyoungpeople.
RogerRosenblatt’sbookBlackFiction,inattemptingtoapplyliteraryratherthansociopoliticalcriteriatoitssubject,succe
Thereisanewtypeofadvertisementbecomingincreasinglycommoninnewspaperclassifiedcolumns.Itissometimesplacedamong
Suicideterrorismisthereadinesstosacrificeone’slifeintheprocessofdestroyingorattemptingtodestroyatargettoadv
随机试题
下列句子中,句式与其他三句不同的是()。
现行税法规定,工资、薪金所得,以每月收入额减除费用多少元后的余额,为应纳税所得额()
下述有关左心室附壁血栓的记述中,哪项是恰当的
便前出血,或便后出血,或粪中带血,以及痔疮出血,血色鲜红或晦暗。方剂选用
某次考试,得分不超过30分的有153人,平均24分;得分不低于80分的有59人,平均92分;得分超过30分的平均62分,得分低于80分的平均54分。则这次考试有多少人参加?
2004—2011年,我国GDP名义同比增长率超过20%的有:
改革开放以来,特别是党的十六大以来,我国文化体制改革由点到面、逐步推开,取得重大突破和阶段性成果。但文化体制改革成果还不够稳固,一些制约文化发展的深层次矛盾和问题还比较突出。党的十八届三中全会提出进一步深化文化体制改革的决定,在构建现代公共文化服务体系方面
Whatisthefirstchoiceforabosstohireanewworker?Whatisthemainideaofthepassage?
______sherealizeditwastoolatetogohome.
TheorganizationbehindtheLawSchoolAdmissionTestreportedthatthenumberoftestsitadministeredthisyeardroppedbymor
最新回复
(
0
)