In February 2006, Lydia Angyiou and her two sons were walking through their village in northern Canada.The sound of children shouting made her turn around.To her horror, Lydia saw  a 700-pound polar bear behind her eyeing her seven-year-old son.Getting between the bear and her child, Lydia yelled at the children to run away.She then began hitting and kicking the animal as hard as she could.A neighbor who heard all the noise came and shot the bear.But everyone agreed it was Lydia who had saved her children's lives.A local policeman described it this way: "…I guess when your back is up against the wall, …we come up with super-human strength."

       Where does this "super-human strength" , courage and quick thinking come from? Experts say it comes from stress! In stressful situations, the body releases chemicals that prepare it to take action.These chemicals give people the speed and strength they need to fight danger or run away from it.

       When we think of stress, we usually think of its negative effects.Studies, though, show that moderate levels of stress are actually helpful.In fact, the way we perform is usually affected by the amount of stress we feel.

       Stress causes the brain to release adrenaline (肾上腺素) which in turn increases our energy and excitement.The chemical gives us clearer minds and helps us to do more.This is why some people say they work better under a deadline.

       Adrenaline that is not released for long periods of time can cause us to increase and strengthen our abilities instead of weakening them.We sometimes turn out our very best work when we push ourselves to the limit.Stress can also make us more confident.Handling small amounts of stress now prepares us for handling serious situations in the future.Who knows? Today's stress may even prepare for the next polar bear that comes along!

55.In the first paragraph, the case of Lydia Angyiou is mentioned to ______.

       A.introduce the topic to be followed

       B.praise Lydia Angyiou for her bravery

       C.remind us of the unexpected danger of life

       D.show the importance of super-human strength

56.What does the policeman probably mean by saying "your back is up against the wall"?

       A.You are helped.            B.You are inspired.

       C.You are confident.          D.You are cornered.

57.What would be the best title for the passage?

       A.Brave Mother          B.The Cause of Stress

    C.The Benefit of Stress    D.Super-human Strength

 Plants are very important living things. Life could not go on if there were no plants. This is because plants can make food from air, water and sunlight. Animals and man cannot make food from air, water and sunlight. Animals get their food by eating plants and other animals. Therefore animals and man need plants in order to live. This is why we find that there are so many plants around us. If you look carefully at the plants around you, you will find that there are two kinds of plants: flowering plants and non-flowering plants. Flowering plants can make seeds. The seeds are protected by the fruits. Some fruits have one seed, some have two, three or four, and some have many seeds. But a few fruits have no seeds at all. An example of a fruit without seeds is the banana fruit. Most non-flowering plants do not grow from seeds. They grow from spores(胚芽)。 Spores are very small. Some spores are so small and light that they can float in the air. We may say that spores are quite the same as seeds. When these spores are all on wet and shady places, they usually grow into new plants.

    55. The main idea of the first paragraph is that ______.

    A. plants are important for life        B. plants cannot grow without air

    C. there are many plants in the world   D. we can not live without water

    56. Plants can make food from______.

    A. flower, water and air            B. water, sunlight and air

    C. air, water and soil               D. air, sun and light

    57. What can we infer(推断) from the passage ?

    A. Of all living things animals are most important B. Spores are seeds

    C. All fruits of flowering plants have seeds D. Without plants, man will die out

    58. This passage may be taken from______.

    A. a medicine book                 B. a novel

    C. a science magazine               D. an experiment report

    59. The underlined word “protected” in the third paragraph can be replaced by ______.

A. damaged       B. polluted       C. prevented       D. guarded

阅读下面短文,用英语回答文后所给的5个问题。

Bacteria(细菌) are extremely small living things. While we measure our own sizes in inches or centimeters, bacterial size is measured in micron. One micron is a thousandth of a millimeter; a pinhead is about a millimeter across. Rod-shaped bacteria are usually from two to four microns long, while rounded ones are generally one micron across. Thus, if you magnified a rounded bacterium a thousand times, it would be just the size of a pinhead, while a grown-up human enlarged by the same amount would be over a mile tall.

Even with an ordinary microscope(显微镜), you must look closely to see bacteria. Using a magnification of 100 times, one can hardly find bacteria. Nor can one make out anything of their structure(结构), of course. Only by using special colors, can one see that some bacteria have wavy-looking “hairs” called flagella. Others have only one flagellum. The flagella move round a central point, pushing the bacteria through the water. Many bacteria lack flagella and cannot move about by their own power, while others can move along over surface by some little-understood “machinery”.

From the bacterial point of view, the world is a very different place from what it is to humans. To a bacterium, water is as thick as molasses(糖浆) is to us. Bacteria are so small that they are affected by the movements of the chemical molecules(分子) around them. Bacteria under microscopes, even those with no flagella, often jump up and down in the water. This is because they knock with the water molecules and are pushed this way and that.

47. What does the underlined word “magnified” mean?

________________________________________________________________

48. What is the smallest according to the passage?

________________________________________________________________

49. What is the relationship between a bacterium and its flagella is most nearly like?

________________________________________________________________

50. Why does the writer compare water to molasses in the third paragraph?

________________________________________________________________

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