题目列表(包括答案和解析)
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 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 volcanic eruption in Iceland has sent ash across northern Europe. Airlines have stopped or changed the flights across the Atlantic Ocean, leaving hundreds of passengers stuck in airports.
Grirmsvom is one of the largest and most active volcanoes in Europe. What makes Grimsvom different is that it lies under a huge glacier（冰川） of ice up to 12 maters thick. The hot volcano heats up the ice above it, which then forms a layer（层）of water between the glacier and the volcano This layer of water puts pressure on the volcano, keeping it stable, As the water flows out from under the glacier, the pressure lifts. The lava（岩浆） from the volcano then comes up to the surface. This is exactly what happened today.
Now, airlines have to make changes to their flights so as not to fly through the clouds of volcanic ash. According to KLM. one of Europe’s biggest airlines, airplanes cannot go under the cloud or over it. Going through the cloud can result in ash getting stuck in the airplane’s engines, causing damage to the plane.
The eruption has also caused problems for animals in Iceland. The volcano left ash and sharp. Glass-like rocks all over the countryside. Farmers are keeping their animals inside to stop them from eating ash- covered grass to the sharp object.
What keeps Grimsvom still?
A. The slow flow of water B. The low water temperature
C. The thick glacier D. The water pressure
Which of the following is true?
A. People stop traveling in Europe
B. Airlines suffer from the loss of planes
C. It becomes dangerous for animals to eat outside
D. Farmers have lost many of their animals
This text is most probably taken from_______________.
A. a research paper B. a newspaper report
C. a class presentation D. a geography textbook.
A popular saying goes, “Sticks and stones may break my bones, but words will never hurt me.” However, that’s not really true. Words have the power to build us up or tear us down. It doesn’t matter if the words come from someone’s else or ourselves --- the positive and negative effects are just as lasting.
We all talk to ourselves sometimes. We’re usually too embarrassed to admit it, though. In fact, we really shouldn’t be because more and more experts believe talking to ourselves out loud is a healthy habit.
This “self-talk” helps us motivate ourselves, remember things, solve problems, and calm ourselves down. Be aware, though, that as much as 77% of self-talk tends to be negative. So in order to stay positive, we should only speak words of encouragement to ourselves. We should also be quick to give ourselves a pat on the back. The next time you finish a project, do well in a test, or finally clean your room, join me in saying “Good job!”
Often, words come out of our mouths without us thinking about the effect they will have. But we should be aware that our words cause certain responses in others. For example, when returning an item to a store, we might use warm, friendly language during the exchange. And the clear will probably respond in a similar manner. Or harsh（刻薄的）and critical language will most likely cause the clerk to be defensive.
Words possess power because of their lasting effect. Many of us regret something we once said. And we remember unkind words said to us! Before speaking, we should always ask ourselves: Is it loving? Is it needed? If what we want to say doesn’t pass this test, then it’s better left unsaid.
Words possess power: both positive and negative. Those around us receive encouragement when we speak positively. We can offer hope, build self-esteem（自尊）and motivate others to do their best. Negative words destroy all those things. Will we use our words to hurt or to heal? The choice is ours.
The main idea of the first paragraph is that ________.
A. not sticks and stones but words will hurt us
B. inspiring words give us confidence
C. negative words may let us down
D. words have a lasting effect on us
There is no sense for us to feel embarrassed when we talk to ourselves because _______
A. almost everybody has the habit of talking to themselves
B. we can benefit from talking to ourselves
C. talking to ourselves always gives us courage
D. it does no harm to have “self-talk” when we are alone
The underlined part in the third paragraph means that we should also timely _______
A. praise ourselves B. remind ourselves
C. make ourselves relaxed D. give ourselves amusement
The author would probably hold the view that ___________
A. encouraging words are sure to lead to kind offers
B. negative words may stimulate us to make more progress
C. people tend to remember friendly words
D. it is better to think twice before talking to others
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