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 E Anti-bird flu contingency measures, including a proposal to separate poultry from humans and a series of traffic and logistics measures will be discussed at the Legislative Council's Food Safety and Environmental Hygiene Panel meeting next month. Secretary for Health, Welfare and Food Dr York Chow says the contingency plan would come into force if an outbreak occurred near Hong Kong. Speaking on a radio talk show this morning, Dr Chow said the separation of poultry from humans policy, which will be determined after a decision whether to set up a central slaughtering house or several regional ones, would be based on the demand for live chickens. He pointed out that at present there were 30,000 live chickens imported from the Mainland and 30,000 supplied locally. If this demand persisted, there would be no central slaughtering house or wholesale point that could handle such an amount and regional slaughtering houses could be the choice. He added that building of regional slaughtering houses took time, but stressed the need to study the views of the public and the sector before a final decision was made. Regarding avian flu vaccination for humans, Dr Chow said it was still being developed. He added that it may not be reliable in the case of an outbreak as records show vaccination can only offer 5% protection against a virus. He said Hong Kong had more experience and expertise than neighbouring territories in the fight against viral outbreaks, and was willing to offer them help. He added there was no “boundary for infectious diseases and close cooperation among different countries had to be maintained to fight against a possible outbreak. 查看更多

 

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

查看答案和解析>>

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 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

查看答案和解析>>

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!

  1. 1.

    When the star begins to die ______.

    1. A.
      there is no fuel left in it
    2. B.
      its outer layer goes into space first
    3. C.
      a huge explosion will happen
    4. D.
      it doesn’t give off light any longer
  2. 2.

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

    1. A.
      The gravity inside the star is very strong.
    2. B.
      The light can’t go out of the star.
    3. C.
      The star becomes smaller and smaller
    4. D.
      The dying star shines very brightly.
  3. 3.

    The black hole ______.

    1. A.
      continues becoming smaller and smaller all the time
    2. B.
      goes into another universe and becomes a white hole
    3. C.
      can pull in everything we know of in the world
    4. D.
      will appear at another place at a different time
  4. 4.

    What’s the best title for this passage?

    1. A.
      A New Scientific Discovery: Black Holes
    2. B.
      How Do Black Holes Come Into Being?
    3. C.
      What Are Black Holes?
    4. D.
      Travel Through A Black Hole

查看答案和解析>>

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

查看答案和解析>>

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

查看答案和解析>>


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