题目内容
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.
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!
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
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.
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
Early one morning, more than a hundred years ago, an American inventor called Elias Howe finally fell asleep. He had been working all night on the design of a sewing machine but he had run into a very difficult problem: It seemed impossible to get the thread to run smoothly around the needle.
Though he was tired, Howe slept badly. He turned and turned. Then he had a dream. He dreamt that he had been caught by terrible savages whose king wanted to kill him and eat him unless he could build a perfect sewing machine. When he tried to do so, Howe ran into the same problem as before. The thread kept getting caught around the needle. The king flew into the cage and ordered his soldiers to kill Howe. They came up towards him with their spears raised. But suddenly the inventor noticed something. There was a hole in the tip of each spear. The inventor awoke from the dream, realizing that he had just found the answer to the problem. Instead of trying to get the thread to run around the needle, he should make it run through a small hole in the center of the needle. This was the simple idea that finally made Howe design and build the first really practiced sewing machine.
Elias Howe was not the only one in finding the answer to his problem in this way.
Thomas Edison, the inventor of the electric light, said his best ideas came into him in dreams. So did the great physicist Albert Einstein. Charlotte Bronte also drew in her dreams in writing Jane Eyre.
To know the value of dreams, you have to understand what happens when you are asleep. Even then, a part of your mind is still working. This unconscious(无意识的), but still active part understands your experiences and goes to work on the problems you have had during the day. It stores all sorts of information that you may have forgotten or never have really noticed. It is only when you fall asleep that this part of the brain can send messages to the part you use when you are awake. However, the unconscious part acts in a special way. It uses strange images which the conscious part may not understand at first. This is why dreams are sometimes called “secret messages to ourselves”.
1.According to the passage, Elias Howe was________.
A. the first person we know of who solved problems in his sleep
B. much more hard-working than other inventors
C. the first person to design a sewing machine that really worked
D. the only person at the time who knew the value of dreams
2.The problem Howe was trying to solve was________.
A. what kind of thread to use
B. how to design a needle which would not break
C. where to put the needle
D. how to prevent the thread from getting caught around the needle
3.Thomas Edison is spoken of because________.
A. he also tried to invent a sewing machine
B. he got some of his ideas from dreams
C. he was one of Howe’s best friends
D. he also had difficulty in falling asleep
4.Dreams are sometimes called “secret messages to ourselves” because ________.
A. strange images are used to communicate ideas
B. images which have no meaning are used
C. we can never understand the real meaning
D. only specially trained people can understand them
This morning as I was getting the children ready or school, I helped them prepare breakfast and pack their lunches. I reviewed spelling words with them and made sure that their homework was collected in their bags. I had seen the weather forecast for the day and knew it was going to remain cool all day. I suggested they wear sweaters for the walk to the us stop. My kids chose to repulse my advice. My son decided that all he needed was a T-shirt, not a sweater.
I didn’t force(强迫) them to wear sweaters and we went to the bus stop. It is a full kilometer walk to the top of a treeless hill and the wind felt like a knife cutting through the skin. My children endured(忍受) the cold until halfway, when I gave them with the sweaters I had quietly carried under my arm. Then took them without complaint, and I bit my tongue from saying, “I told you so.”
What I was asking my children to do was to trust me. Trust Mom to have their best interests in mind. Trust Mom to know what she is talking about. Even though they didn’t know that I had read the outdoor thermometer (温度计) before they woke up and I had seen the day’s weather forecast, I wanted them to trust me. By ignoring me, they were saying that they didn’t believe I knew what was best for them. What they knew was that yesterday was a warm enough day for shorts. What they knew was that it was warm enough in the house to wear shorts. Therefore, they felt sure enough to make their own decision on what to wear outside.
Too many times we depend on what we know of yesterday, and how we feel today, and so we make decisions based on them. Too many times we think that we know better, so we can deal with things better. But we are wrong.
1.It can be inferred from the first paragraph that .
A．the author didn’t believe in her children
B．the author took her children to school every morning
C．the author’s children always followed her advice
D．the author had a very busy morning that day
2.The underlined word “repulse” in the first paragraph means .
A．refuse B．follow C．seek D．doubt
3.What can be learned from the passage?
A．The author’s children always ignore her.
B．The author takes great care of the children in life.
C．The author’s children always make wrong decisions.
D．The author always force her children to wear sweaters.
4.The author writes this passage to .
A．tell the readers how to ask for advice
B．offer advice on how to teach children
C．explain the importance of trusting others
D．give advice on how to make decisions
