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 go out. 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 hole 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 use 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 some day be used to swallow earthly waste—a sort of huge waste disposal (处理) in the sky!

When the star begins to die ______.

       A．there is no fuel left in it B．its outer layer goes into space first

       C．a huge explosion will happen        D．it doesn’t give off light any longer

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

       A．The gravity inside the star is very strong.

       B．The light can’t go out of the star.

       C．The star becomes smaller and smaller

       D．The dying star shines very brightly.

The black hole ______.

       A．continues becoming smaller and smaller all the time

       B．goes into another universe and becomes a white hole

       C．can pull in everything we know of in the world

       D．will appear at another place at a different time

What’s the best title for this 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

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 billions 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 go out．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 for the time being, the black hole 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 use 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 would some day be used to swallow earthly waste — a sort of huge waste disposal（处理） unit in the sky！

1．When the star begins to die, ______

       A．there is no fuel left in it                   B．its outer layer goes into space first

       C．a huge explosion will happen               D．it doesn’t give off light any longer

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

       A．The gravity inside the star is very strong．

       B．The light can’t go out of the star.

       C．The star becomes smaller and smaller．

       D．The dying star shines very brightly.

3．The black hole ______.

       A．continues becoming smaller and smaller all the time

       B．goes into another universe and becomes a white hole

       C．can pull in everything we know of in the world

       D．will appear at another place at a different time

4．The best title for this passage is _______.

       A．What Are Black Holes

       B．Travel through a Black Hole

       C．How Do Black Holes Come into Being

       D．A New Scientific Discovery: Black Holes

 Are you a man or a mouse? When people ask this question they want to know 31   you are a   32  person or a coward(懦夫). But you will never really know the answer to this question  33  you are tested in real life. Some people  34  they are brave but when they come face to face with real  35 , they act like cowards. Others think of themselves as cowards, but when they meet danger, they act like  36 .

Lenny had always thought of himself as a  37  person. He got worried before examinations. He worried about his job and health. All he wanted in life was to be safe and healthy.  38 , on January 15^th, 2002, a plane crashed into the Potomac River in Washington. Lenny went to the river to see what was happening. He saw a woman in the  39  water. Lenny did not feel afraid. He kept very  40  and did a very dangerous thing. He jumped into the Potomac, 41  to the woman, and kept her head  42  the water. Seventy-eight people died that day. Thank to Lenny, it was not  43 .

When you are in a very  44  situation and feel afraid, the body automatically produces a chemical in the blood. The chemical is called adrenalin(肾上腺素). 45 adrenalin in the blood system, you will feel stronger and stronger and are  46 to fight or run away. However, when you are absolutely terrified, the body can produce too much adrenalin. When this  47 , the muscles become very hard and you find you  48  move at all. You are then paralyzed(使瘫痪，使麻痹) with fear. This is  49  when we are very frightened, we sometimes say we’re “petrified”, which means “stone”. We are   very frightened 50  we become stonelike.

1.                A．how           B．neither         C．whether  D．either

 

2.                A．brave          B．real            C．hard D．certain

 

3.                A．when          B．until           C．after D．once

 

4.                A．realize         B．find            C．think D．agree

 

5.                A．life            B．question        C．mouse   D．danger

 

6.                A．soldiers        B．mice           C．heroes   D．cowards

 

7.                A．useful          B．brave          C．nervous  D．terrible

 

8.                A．So             B．Therefore       C．Then D．Actually

 

9.                A．fresh          B．poisonous       C．warm D．ice-cold

 

10.               A．nervous        B．calm           C．frightened D．excited

 

11.               A．went          B．helped         C．spoke D．swam

 

12.               A．in             B．under          C．above D．from

 

13.               A．an accident     B．a mistake       C．seventy-eight   D．seventy-nine

 

14.               A．dangerous      B．comfortable     C．different  D．favorable

 

15.               A．With           B．Without        C．For   D．Like

 

16.               A．afraid          B．unable         C．ready D．anxious

 

17.               A．gets           B．disappears      C．happens   D．goes

 

18.               A．needn’t       B．can’t         C．mustn’t  D．shouldn’t

 

19.               A．where         B．how           C．because   D．why

 

20.               A．that           B．for            C．such  D．so

 

 

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 go out. 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 hole 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 use 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 some day be used to swallow earthly waste—a sort of huge waste disposal (处理) in the sky!

When the star begins to die ______.

       A．there is no fuel left in it        B．its outer layer goes into space first

       C．a huge explosion will happen        D．it doesn’t give off light any longer

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

       A．The gravity inside the star is very strong.

       B．The light can’t go out of the star.

       C．The star becomes smaller and smaller

       D．The dying star shines very brightly.

The black hole ______.

       A．continues becoming smaller and smaller all the time

       B．goes into another universe and becomes a white hole

       C．can pull in everything we know of in the world

       D．will appear at another place at a different time

The author mainly intended to tell us _____.

       A．A New Scientific Discovery: Black Holes

       B．How Black Holes Came Into Being

       C．What Black Holes Are

       D．Travel Through A Black Hole