首页
登录
职称英语
[img]2014m4s/ct_eyyjsdz2012j_eyyjsdreada_0370_20139[/img] It is just about i
[img]2014m4s/ct_eyyjsdz2012j_eyyjsdreada_0370_20139[/img] It is just about i
游客
2024-08-21
10
管理
问题
It is just about impossible to imagine how big the universe is. All we can do is to describe certain things we know about it and hope that these give an idea of the scale of the cosmos.
On clear nights, in places where light pollution from cities does not make it too difficult to see the stars, we can see many points of lights in the sky which are like a white cloud of stars. This is our home galaxy, the Milky Way. There are probably as many or more galaxies in the universe as there are stars in the Milky Way. Some estimates say there are 100 billion galaxies, each with millions of stars. Our home galaxy, like all others, is still forming stars all the time from gas floating in space.
Most galaxies contain not only stars, but also black holes. These are the tiny remains of stars that have collapsed in spectacular explosions. Gravity is so intense in black holes that light bends, so it can’t escape to be seen from outside. The mass of a black hole is so concentrated that the Earth would be reduced to the size of a tennis ball, while remaining as heavy as it is now.
Our nearest neighboring galaxy is Andromeda, which is two million light years away. A light year is the distance covered by light during one year, traveling at 300, 000 kilometers a second. The most distant galaxies that we can see, even with telescopes, are 10 to 12 billion light years a-way. That means it has taken the light from those galaxies that amount of time to reach the Earth. When that light left those galaxies, the universe was still quite young. The universe began with a gigantic explosion, called the Big Bang. About 14 to 15 billion years ago, something about the size of an atom suddenly started expanding dramatically. Out near the edge of the universe, there is still Cosmic Microwave Background, which is the heat left over from the Big Bang. Today the universe is still expanding in a process called inflation. And it may go on accelerating outwards from the original point for ever. The latest theories show that only a tiny proportion of the universe is made up of the kind of matter that we can see: about 15% of it is something called dark matter, and the rest, about 75% , is dark energy, which is driving the inflation of the universe. [br] What would happen to the Earth in a black hole?
选项
A、It would become very tiny and light.
B、It would remain the same weight.
C、It would start bending light.
D、It would become much heavier.
答案
B
解析
根据第三段…the Each would be reduced to the size of a tennis ball,while remaining asheavy as it is now.可知。如果地球进了黑洞会变成网球那么大,但是重量却不变,故选B。
转载请注明原文地址:https://tihaiku.com/zcyy/3728834.html
相关试题推荐
[img]2012q2/ct_eyyjsdz2009b_eyyjsdreada_0292_20121[/img]Doyoueverwonder
[img]2012q2/ct_eyyjsdz2009b_eyyjsdreada_0292_20121[/img]Doyoueverwonder
[img]2012q2/ct_eyyjsdz2009a_eyyjsdreada_0219_20121[/img]Theopeningofyour
[img]2012q2/ct_eyyjsdz2009a_eyyjsdreada_0219_20121[/img]Theopeningofyour
[img]2012q2/ct_eyyjsdz2009a_eyyjsdreada_0219_20121[/img]Theopeningofyour
[img]2012q2/ct_eyyjsdz2009a_eyyjsdreada_0219_20121[/img]Theopeningofyour
[img]2012q2/ct_eyyjsdz2010b_eyyjsdreada_0162_20121[/img]Manyculturesfollo
[img]2012q2/ct_eyyjsdz2010b_eyyjsdreada_0162_20121[/img]Manyculturesfollo
[img]2012q2/ct_eyyjsdz2010b_eyyjsdreada_0162_20121[/img]Manyculturesfollo
[img]2012q2/ct_eyyjsdz2010b_eyyjsdreada_0162_20121[/img]Manyculturesfollo
随机试题
TreesTomany,thewordtreesevo
Musicians—fromkaraokesingerstoprofessionalviolinplayers—arebetterabl
()等特种作业人员,必须按照国家有关规定经过专门的安全作业培训,并取得特种作业
下列关于反向购买的表述中,不正确的有( )。A.反向购买是同一控制下企业合并
人类白化病是常染色体隐性遗传病。某患者家系的系谱图如下,显性基因为A,隐性基因为
总需求曲线向下方倾斜的原因是()。A.随着价格水平的下降,居民的实际财富
关于圆癣的描述,以下哪项不正确A:好发于长夏高温、潮湿季节 B:好发于面部、躯
租赁合同中,租赁期间届满,当事人可以续订租赁合同,但约定的租赁期限自续订之日起不
许又新提出的心理健康标准包括()。多选A.体验标准 B.操作标准 C.
男,50岁。幽门梗阻持续胃肠减压半个月,每日10%葡萄糖2500mL,5%葡萄糖
最新回复
(
0
)