Question

    A black hole is created when a large star burns out. Like our sun, stars are unbelievably hot furnaces (熔炉) that burn their own matter as fuel. When most of the fuel is used up, the star begins to die.

The death of a star is not a quiet event. First, there is a huge explosion. As its outer layer is blasted off into space, the dying star shines as brightly as a billion suns.

After the explosion, gravity pulls in what’s left of the star. As the outside of the star sinks toward the center, the star gets smaller and smaller. The material the star is made of becomes tightly packed together. A star is so dense that a teaspoon of matter from it weighs billion of pounds.

The more the star shrinks, the stronger the gravity inside it becomes. Soon the star is very tiny, and the gravity pulling it in is unbelievably strong. In fact, the gravity is so strong that it even pulls light into the star! Since all the light is pulled in, none can flee. The star becomes black when there is no light. Then a black hole is born!

That’s what we know about black holes. What we don’t know is this: What happens inside a black hole after the star has been squeezed into a tiny ball? Does it keep getting smaller and smaller forever? Such a possibility is hard to imagine.

But if the black hole doesn’t keep shrinking, what happens to it? Some scientists think black holes are like doorways to another world. They say that as the star disappears from our universe, it goes into another universe. In other words, a black hole in our universe could turn into a “white hole” in a different universe. As the black hole swallows light, the white hole shines brightly — somewhere else. But where? A different place, perhaps, or a different time — many years in the past or future.

Could you travel through a black hole? Right now, no. Nothing we know of could go into a black hole without being crushed. So far the time being, black holes must remain a mystery.

Black holes are a mystery — but that hasn’t stopped scientists from dreaming about them. One scientist suggested that in the future we might make sure of the power of black holes. They would supply all of Earth’s energy needs, with plenty to spare. Another scientist wondered if a black hole could someday be used to swallow earthly waste — a sort of huge waste disposal in the sky!

1.What do we know about stars in the universe?

A.When a star begins to die, there’s no fuel left in it.

B.After the explosion, a star gets as small as a teaspoon.

C.A star explodes when it dies and then becomes smaller and smaller.

D.A star gets smaller and smaller because the outer layer of a star sinks toward the center.

2.Which of the following doesn’t help produce a black hole?

A.The dying star shines very brightly. B.The light can’t go out of the star.

C.The gravity inside the star is very strong. D.The star becomes very tiny and dense.

3.What can we know from the passage?

A.A star will blast and die when it lacks fuel to support its burning.

B.Man can never travel through a black hole but can make use of its power.

C.A black hole can swallow everything because it becomes smaller all the time.

D.Scientists have found that a black hole goes into another universe and becomes a white hole.

4.What is the best title for the passage?

A.A New Scientific Discovery: Black Holes B.How Do Black Holes Come into Being?

C.What Are Black Holes? D.Travel Through A Black Hole

Answer

1.C

2.A

3.A

4.B

【解析】

本文是说明文。文章阐述了黑洞产生的原因、产生的过程以及科学家们关于黑洞的形成更多的困惑。

1.

细节理解题。文章第一段中提到“When most of the fuel is used up, the star begins to die.”，第二段中提到“The death of a star is not a quiet event. First, there is a huge explosion.”以及第三段中提到“After the explosion, gravity pulls in what’s left of the star. As the outside of the star sinks toward the center, the star gets smaller and smaller.”由此可知，当恒星大部分燃料耗尽时，恒星就开始消亡，首先是爆炸。爆炸后，引力会把恒星剩余的部分吸进来，恒星会变得越来越小。故选C项。

2.

细节理解题。文章第三段中提到“the star gets smaller and smaller. …A star is so dense that a teaspoon of matter from it weighs billion of pounds.”，恒星变得越来越小，密度变得非常大；第四段解释黑洞形成的原因“The more the star shrinks, the stronger the gravity inside it becomes. Soon the star is very tiny, and the gravity pulling it in is unbelievably strong. In fact, the gravity is so strong that it even pulls light into the star! Since all the light is pulled in, none can flee. The star becomes black when there is no light. ”可知，恒星收缩，其内部的引力增强。引力是如此强大，它甚至把光吸进恒星！没有光能逃出去。没有光，恒星就变黑了。然后黑洞形成了。由此可知，选项B、C和D都是黑洞形成的原因；根据“Since all the light is pulled in, none can flee. The star becomes black”可知，快消亡的恒星是不会发出明亮的光的。选A项。

3.

细节理解题。根据文章第一段中“A black hole is created when a large star burns out. …When most of the fuel is used up, the star begins to die.”和第二段中“First, there is a huge explosion.”可知，恒星燃料耗尽，缺乏燃料支持其燃烧时，就会爆炸并开始消亡。故选A项。

4.

主旨大意题。通读全文，文章首句提到“A black hole is created when a large star burns out.(当一颗恒星燃烧殆尽时，黑洞就产生了)”说明黑洞产生的原因是因为星体燃料耗尽，开始消亡；第2至4段是说明黑洞产生的过程；第5至8段是科学家们关于黑洞的形成有更多的困惑和猜测。文章是关于黑洞的形成，因此文章的标题应该为“黑洞是如何形成的？”故选B项。