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”(超大質(zhì)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.

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

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.

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.

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”.

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

 

1.A

2.C

3.C

4.D

5.D

【解析】

試題分析：文章大意：文章介紹黑洞的形成，它的特點(diǎn)以及科學(xué)家探索研究黑洞的方法。

1. can happen when a star is dying.”可知恒星的死亡可能會(huì)形成黑洞。故選A。

2. black holes are very tiny but have the mass of a large mountain”這些黑洞可能會(huì)非常小，但是有一座山一樣的質(zhì)量，可知A正確；根據(jù)倒數(shù)第二段中“A black hole can not be seen because strong gravity pulls all of the light into the middle of the black hole.”黑洞不可見(jiàn)是因?yàn)閺?qiáng)大的引力將所有的光線吸進(jìn)黑洞的中間，可知B項(xiàng)正確；根據(jù)最后一句“Scientists use satellites and telescopes in space to see the high-energy light.”科學(xué)家們使用衛(wèi)星和太空望遠(yuǎn)鏡查看高能光，可知科學(xué)家不是用自己的眼睛，因此C錯(cuò)誤；根據(jù)第六段中“Scientists think the smallest black holes formed when the universe began.”科學(xué)家認(rèn)為最小的黑洞在宇宙開(kāi)始時(shí)形成，可知D項(xiàng)正確。故選C。

3. galaxy is called the Milky Way”地球所在的星系叫銀河系，常理可知星系是有很多星星組成的。故選C。

4. 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.”在銀河系中心的超大質(zhì)量黑洞的質(zhì)量相當(dāng)于四百萬(wàn)個(gè)太陽(yáng),是一個(gè)可以容納幾百萬(wàn)地球在內(nèi)的巨大的球，由此可知這是在解釋什么叫做“超大質(zhì)量黑洞”。故選D。

5.

考點(diǎn)：考查科普教育類(lèi)閱讀

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