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

B

From E-mail to online shopping, you may think you’ve heard everything there to know about the electronic frontier （新领域）．But with hundreds of thousands of Web pages being added weekly, there are plenty of surprises out there．Here are some of the most intriguing （有迷惑力的）．

……

Put your kid on a greeting card．Here is how: simply take some pictures with a regular camera, and then ask the photo service to develop them digitally （数字化）．For a small fee, you’ll receive your photos on a desk．Put that into your computer and, with a few clicks of the mouse, you can view your photos on the screen．With a few more keystrokes, you can attach the photos to email and send them to friends and relatives worldwide．

　　Sign on to one or several greeting card’s Websites （http://www．cardcentral．net/ is an index of more than 1200 electronic card sites） and create an electronic birthday or holiday card．Using your digital photos, you can paste your grandchildren onto the cover．

　　If you don’t want to use your own photos, go to cards．amzon．com to browse （浏览） hundreds of images in over 30 categories…all of which you can attach to an electronic greeting card for free．For a nominal fee（很低的费用）you can choose from a library of 75,000 images at http://www．phontodisc．com/．

　　Call Australia for free．To have a telephone conversation over the Internet, the person you want to talk to no longer needs a computer．Now all you need to talk to someone in Sydney is one computer with speakers, a microphone, a sound card and some software （available at http://www．vocaltec．com/ or Mricrosoft．com）．Typically, you’ll pay a monthly fee （usually under $20） to a service provider, but after that, the calls themselves are local．Sound quality is the same as that of a cell phone．

　　Even if you don’t have a computer, you can still use the Web to reduce your long distance phone costs．Some companies offer a service that lets you use an ordinary phone to call another ordinary phone, but charge only a few cents per minute for US calls, because they send them through the Internet．

　　Today 48 percent of American homes have computers…a figure that is expected to climb to 60 percent by 2003．And by the end of the next decade, Americans will likely be spending more time shopping, banking, investing and learning on the Internet than in the real world．If you can’t do or find something on the Net today, you probably can tomorrow．

60．Over the Internet, you ________．

       A．can hear everything there

       B．will meet with plenty of surprises which come out every week．

       C．will hear the things about the electronic frontier

       D．can find some things are very interesting

61．From the passage we can infer that _________．

       A．fewer people will use the Internet in the following ten years

       B．more people will study in the regular school by the end of the next decade

       C．fewer people will go to the regular school in the following ten years

       D．more money will be needed for a long-distance call by the end of the next decade

62．If you want to attach to photo to your e-mail, you have to ________ it．

       A．digitalize　　  B．take　　　　   C．picture　　　　      D．send

63．Which of the following is NOT true?

       A．A telephone conversation over the Internet can be carried out without computers．

       B．Over the Internet, the receiver of the phone conversation doesn’t need a computer．

       C．The phone conversations over the Internet are much cheaper．

       D．The long-distance calls are local themselves．

       A recent study, while showing a generally positive attitude toward science, also suggests a widespread worry that it may be “running out of control”．This idea is dangerous．

       Science can be a force for evil as well as for good．Its applications can be channeled either way, depending on our decisions．The decisions we make, personally or collectively, will determine the outcomes of science．But here is a real danger．Science is advancing so fast is so strongly influenced by businesses that we are likely to believe whatever decisions we come to will make little difference．And, rather than fighting for the best possible policies, we may step back and do nothing．

       Some people go even further．They say that despite the moral and legal objections （反对）, whatever is scientifically possible will be done ——somewhere, sometime．They believe that science will get out of control in the end．This belief is dangerous too, because it a fuels sense of hopelessness and discourages them from making efforts to build a safer world．

       In our interconnected world, the lack of agreement in and of the world of science can lead to the failure to control the use of science．Without a common understanding, the challenges of “controlling” science in this century will be really tough．Take human cloning for example．Despite the general agreement among scientists on its possible huge impact （影响） on traditional moral values, some countries still go ahead with the research and development of its related techniques．The outcomes are hard to predict．

       Therefore, discussions on how science is applied should be extended far beyond scientific societies．Only through the united efforts of people with hope, can we be fully safe against the misuse of science and can science best serve mankind in the future．

What can we conclude from the recent study?

       A．People think highly of science．

       B．People hold mixed opinions about science．

       C．Science is getting dangerously out of control．

       D．Science is used for both good and bad purposes．

According to the passage, what will happen if we hold that science is getting beyond control?

       A．The development of science will hopelessly slow down．

       B．Businesses will have even greater influence on science．

       C．The public will lose faith in bringing about a bright future．

       D．People will work more actively to put science under control．

The discussion should reach beyond scientific societies because __________．

       A．scientists have failed to predict the outcomes

       B．the ties between different areas need strengthening

       C．united efforts are necessary for the development of science

       D．people need to work together to prevent the bad use of science

What is the main idea of the passage?

       A．Science and its applications bring us many dangers．

       B．The development of science mostly lies in people’s attitudes．

       C．Mankind can largely take control of science with their efforts．

       D．The future of science will be influenced by the dangerous ideas．

A rainforest is an area covered by tall trees with the total high rainfall spreading quite equally through the year and the temperature rarely dipping below l6℃．Rainforests have a great effect on the world environment because they can take in heat from the sun and adjust the climate．Without the forest cover，these areas would reflect more heat into the atmosphere，warming the rest of the world. Losing the rainforests may also influence wind and rainfall patterns，potentially causing certain natural disasters all over the world．

    In the past hundred years，humans have begun destroying rainforests in search of three major resources(资源): land for crops，wood for paper and other products，land for raising farm animals．This action affects the environment as a whole．For example，a lot of carbon dioxide(二氧化碳) in the air comes from burning the rainforests．People obviously have a need for the resources we gain from cutting trees but we will suffer much more than we will benefit.

    There are two main reasons for this．Firstly，when people cut down trees，generally they can only use the land for a year or two．Secondly，cutting large sections of rainforests may provide a good supply of wood right now，but in the long run it actually reduces the world’s wood supply．

    Rainforests are often called the world’s drug store．More than 25％ of the medicines we use today come from plants in rainforests．However，fewer than l％of rainforest plants have been examined for their medical value．It is extremely likely that our best chance to cure diseases lies somewhere in the world’s shrinking rainforests．

Rainforests can help to adjust the climate because they                ．

  A．reflect more heat into the atmosphere

  B．bring about high rainfall throughout the world

  C．rarely cause the temperature to drop lower than l6℃

  D．reduce the effect of heat from the sun on the earth

What does the word “this” underlined in the third paragraph refer to? 

  A．We will lose much more than we can gain．

  B．Humans have begun destroying rainforests．

  C．People have a strong desire for resources．

  D．Much carbon dioxide comes from burning rainforests．

It can be inferred from the text that      . 

  A．we can get enough resources without rainforests

  B．there is great medicine potential in rainforests

  C．we will grow fewer kinds of crops in the gained land

  D．the level of annual rainfall affects wind patterns

What might be the best title for the text? 

   A．How to Save Rainforests                B．How to Protect Nature

   C．Rainforests and the Environment        D．Rainforests and Medical Development