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A black hole is a place in space where gravity pulls so much that even light cannot get out. The gravity is so strong because matter has been squeezed into a tiny space. This can happen when a star is dying.
Because no light can get out, people can’t see black holes. Space telescopes with special tools can help find black holes. The special tools can see how stars that are very close to black holes act differently from other ones.
Black holes can be big or small. Scientists think the smallest black holes are as small as just one atom. These black holes are very tiny but have the mass of a large mountain. Mass is the amount of matter, or “staff”, in an object.
Another kind of black hole is called “stellar”(星球黑洞). Its mass can be up to 20 times more than the mass of the sun. There may be many stellar mass black holes in Earth’s galaxy. Earth’s galaxy is called the Milky Way.
The largest black holes are called “supermassive”(超大质量黑洞). These black holes have masses that are more than one million suns together. Scientists have found proof that every large galaxy contains a supermassive black hole at its center. The supermassive black hole at the center of the Milky Way galaxy has a mass equal to about four million suns and would fit inside a very large ball that could hold a few million Earths.
Scientists think the smallest black holes formed when the universe began. Stellar black holes are made when the center of a very big star falls in upon itself, or falls apart. When this happens, it exploded part of the star into space. Scientists think supermassive black holes were made at the same time as the galaxy they are in.
A black hole can not be seen because strong gravity pulls all of the light into the middle of the black hole. But scientists can see how the strong gravity affects the stars and gas around the black hole. Scientists can study stars to find out if they are flying around, or orbiting a black hole.
When a black hole and a star are close together, high-energy light is made. This kind of light cannot be seen with human eyes. Scientists use satellites and telescopes in space to see the high-energy light.
【小题1】 The gravity of a black hole may become so strong that light cannot get out when_.
A.the star is going to die
B.special tools are used on it
C.other stars come close to it
D.it is seen from the space telescopes
【小题2】According to the passage, which of the following is NOT true?
A.A black hole can be very tiny but extremely heavy.
B.The gravity of a black hole holds all light in its center.
C.Scientists observe high-energy light through their own eyes.
D.Some small black holes came into being as early as the universe.
【小题3】Which can be inferred from the passage?
A.Every galaxy must have a black hole.
B.A galaxy is the center of the universe.
C.A galaxy consists of a large group of stars and planets.
D.Earth’s galaxy is called the Milky Way.
【小题4】What does the last sentence in Paragraph 5 suggest?
A.Neither the sun nor the earth is as heavy as a black hole.
B.There is only one supermassive black hole at the center of the Milky Way.
C.The supermassive black hole had existed before the Milky Way was formed.
D.There is a reason why the large black holes are called “supermassive”.
【小题5】The last two paragraph mainly focus on the question of _________.
A.what a black hole is
B.how black holes form
C.how big black holes are
D.how scientists know about black holes
答案:【小题1】A
【小题2】C
【小题3】C
【小题4】D
【小题5】D
试题分析:本文主要讲述太空黑洞的形成原因和科学家们如何了解黑洞现象的。
【小题1】A推断题,根据文章的第一段,特别是关键句This can happen
when a star is dying可知黑洞是因为星星的损落造成的。故选A。.
【小题2】C推断题,根据文章的最后一段When a black hole and a star are close together, high-energy light is made. This kind of light cannot be seen with human eyes. Scientists use satellites and telescopes in space to see the high-energy light可知科学家们观察高能量的星星是通过望远镜和卫星观察的,不是用肉眼观察的,故选C。
【小题3】C推断题。根据第五段的Scientists have found proof that every large galaxy contains a supermassive black hole at its center可知银河系是由很多的恒星和行星组成的,故选C。
【小题4】D推断题。根据文章倒数第二段A black hole can not be seen because strong gravity pulls all of the light into the middle of the black hole.和第三段最后一句Scientists think supermassive black holes were made at the same time as the galaxy they are in.推断有很多理由可以解释为什么黑洞可以被成为“supermassive”。故选D。
【小题5】D大意题。文章的最后两段都在说明科学家们是怎么样了解黑洞现象的,故选D。
考点:科普环保类阅读理解