Surveys of American teenagers find that about half of them do not get enough sleep on school nights. They get an average of 60 to 90 minutes less than experts say they need.

Experts say teens are biologically programmed to go to sleep later and wake up later than other age groups. Yet many schools start classes as early as seven in the morning.

As a result，many students go to class feeling like Danny，16 years old. He plays two sports，lacrosse and football. He is an active teen—except in the morning. DANNY：“Getting up in the morning is pretty terrible. I’m just very out of it and tired. And through first and second period I can hardly stay awake.”

Michael Breus，a clinical psychologist with a specialty in sleep disorders says：“These aren’t a bunch of lazy kids—although，you know，teenagers can of course be lazy. These are children whose biological rhythms，more times than not，are off.”Teens，he says，need to sleep eight to nine hours or even nine to ten hours a night. He says sleepy teens can experience a form of depression that could have big effects on their general well-being. It can affect not just their ability in the classroom but also on the sports field and on the road because any tired driver is dangerous，especially a teenager with a lack of experience.

So what can schools do about sleepy students？The psychologist says one thing they can do is start classes later in the morning.

Eric Peterson，head of St.George’s School in the northeastern state of Rhode Island，says，“In the end，schools ought to do what’s the right thing for their students，first and foremost.”And he wanted to see if a 30-minute delay would make a difference. It did.

1.According to the passage，which of the following is the chief cause of sleepy teenagers？

2.According to Michael Breus，         .

3.What is Eric Peterson’s opinion on the issue？

4.What does the underlined word“It”in the last sentence might refer to？

5.What can you infer might follow the passage immediately？

“I’m seventy years old,” says the gray-haired lady proudly to the entertainer at her Community Club dinner.
“Did you hear that, everyone?” says the entertainer. “This lovely lady is just seventy years young! And she doesn’t look a day over fifty.” He has been careful not to use the word “old”. In a society where youth is so admired, old age is often seen as something sad, something to fight against. Americans prefer not to say “old” people. They use the expression “senior citizens”. They do not talk about “old people’s” homes, but “retirement” homes.
In fact, the entertainer is not so wrong. Seventy is not very old these days. People in the US are living longer and longer. In1980, 12 percent of Americans were over sixty-five years old. By 2030, 21 percent will be over sixty-five. One reason for this is that families are getting smaller. The average couple now has only 1.8 children. At the same time, improved medical care means that people are living longer.
This change in the age of Americans is going to have serious results. For one thing, medical costs are rising. The government is unable to pay the elderly people’s medical bills that have gone up very much. Some old people have to leave hospital “sicker and quicker” than they should, before they are really better.
More fortunate senior citizens, though, who still have good health, want new laws to be passed to allow them to stay at work. In the past, the retirement age was sixty-five, but that is changing now. Older people are stronger and more energetic than ever before. Many of them refuse to stop working just because they have reached a certain age.
There is a change, too, in the way in which elderly people see themselves. Many are no longer happy to accept the gray hair, bald heads, and boring clothes of their own parents. They like to wear younger-looking clothes and bright makeup（化妆品）.American women spend millions of dollars a year on operations to lift their faces and make those ugly wrinkles disappear. Men are prepared to spend even more on operations to plant new hair on their bald spots. It’s worth any money to look younger.
60. In America people try to avoid using the word “old” because    ____.
A. the old age is seen as something that isn’t admired
B. it is now believed to bring bad luck to elderly people
C. the standard of getting old has changed  
D. the change in the age has caused a healthy problem
61. According to the passage, which of the following does NOT describe the American society correctly?
A. People live longer because of improved medical care.
B. The government finds it difficult to afford the medical bills of the elderly.
C. People use polite expressions when talking about old age.
D. The old patients’ time in hospital is strictly limited.
62. Which of the following is not the result of the changing in the age of Americans?
A. Medical costs are rising.          
B. The family becomes smaller.
C. The retirement age needs changing. 
D. Elderly people spend a lot on keeping young.
63. This passage is most probably taken from        .
A. a travel booklet     B. a magazine   
C. an advertisement     D. a medical report 

       "I'm seventy years old," says the gray-haired lady proudly to the entertainer at her Community Club dinner.

       "Did you hear that, everyone?" says the entertainer.  "This lovely lady is just seventy years  young! And she doesn't look a day over fifty. "

       He has been careful not to use the word "old".  In a society where youth is so admired, old age is often seen as something sad, something to fight against.  Americans prefer not to say "old" people.  They use the expression "senior citizens".  They do not talk about "old people's" homes, but "retirement" homes.

       In fact, the entertainer is not so wrong.  Seventy is not very old these days.  People in the US are living longer and longer.  In1980, 12 percent of Americans were over sixty-five years old.  By 2030, 21 percent will be over sixty-five.  One reason for this is that families are getting smaller.  The average couple now has only 1. 8 children.  At the same time, improved medical care means that people are living longer.

       This change in the age of Americans is going to have serious results.  For one thing, medical costs are rising.  The government is unable to pay the elderly people's medical bills that have gone up very much.  Some old people have to leave hospital "sicker and quicker" than they should, before they are really better.

       More fortunate senior citizens, though, who still have good health, want new laws to be passed to allow them to stay at work.  In the past, the retirement age was sixty-five, but that is changing now.  Older people are stronger and more energetic than ever before.  Many of them refuse to stop working just because they have reached a certain age.

       There is a change, too, in the way in which elderly people see themselves.  Many are no longer happy to accept the gray hair, bald heads, and boring clothes of their own parents.  They like to wear younger-looking clothes and bright makeup（化妆品）. American women spend millions of dollars a year on operations to lift their faces and make those ugly wrinkles disappear.  Men are prepared to spend even more on operations to plant new hair on their bald spots.  It's worth any money to look younger.

56．In America people try to avoid using the word "old" because        .

      A．the old age is seen as something that isn't admired

       B．it is now believed to bring bad luck to elderly people

       C．the standard of getting old has changed

       D．the change in the age has caused a healthy problem

57．According to the passage,  which of the following does NOT describe the American society correctly?

       A．People live longer because of improved medical care.

       B．The government finds it difficult to afford the medical bills of the elderly.

       C．People use polite expressions when talking about old age.

       D．The old patients' time in hospital is strictly limited.

58．Which of the following is not the result of the changing in the age of Americans?

       A．Medical costs are rising.

       B．The family becomes smaller.

       C．The retirement age needs changing.

       D．Elderly people spend a lot on keeping young.

59．The underlined word "Many", in the last paragraph refers to        .

       A．American adults               B．American old people

       C．young Americans             D．American women

      Sports medicine experts have observed for  years that athletes such as long distance runners, especially women athletes, often display a lack of iron. Now a new study by a team of Purdue University researchers suggests that even moderate exercise may lead to reduced iron in the blood of women.

"We found that women who were normally inactive and then started a program of moderate exercise of middle degree showed sings of iron loss," says Roseanne M. Lyle, associate professor at Purdue. Her study of 62 formerly inactive women who began exercising three times a week for six months was published in the journal Medicine & Science in Sports & Exercise.

Iron deficiency is very common among women in general, affecting one in four female teenagers and one in five women aged 18 to 45, respectively. But the ratio is even greater among active women, affecting up to 80 percent of female endurance athletes. This means, Lyle says, that "too many women ignore the amount of iron they take in". Women of child-bearing age are at greatest risk, since their monthly bleeding is a major source of iron loss. Plus, many health-conscious women increase their risk by rejecting red meat, which contains the most easily absorbed form of iron. And because women often restrict their diet in an effort to control weight, they may not consume enough iron-rich food, and are liable to experience a deficiency.

Exercise can result in iron loss through a variety of mechanisms. Some iron is lost in sweat, and, for unknown reasons, intense endurance exercise is sometimes associated with bleeding of the digestive system. Athletes in high-impact sports such as running may also lose iron through a phenomenon where small blood vessels in the feet leak blood.

There are three stages of iron deficiency. The first and most common is having low iron reserves, a condition that typically has no symptoms. Fatigue and poor performance may begin to appear in the second stage of deficiency, when not enough iron is present to form the molecules(分子) of blood protein that transport oxygen to the working muscles. In the third and final stage, people often feel weak, tired, and out of breath - and exercise performance is severely compromised.

"People think that if they're not at the third stage, nothing is wrong, but that's not true," says John L. Beard, who helped design the Purdue study. "You're not stage 3 until your iron reserves go to zero, and if you wait until that point, you're in trouble."

       Beard and other experts say it’s advisable for people to have a yearly blood test. If iron levels are low, talk with a physician to see if the deficiency should be corrected by changing your diet and taking iron-rich foods or by taking iron-added pills.

 “Select breads and cereals with the words ‘iron-added’ on the label,” writes sports diet expert Nancy Clark. “This added iron supplements the small amount that naturally occurs in grains.” Clark also recommends cooking in iron pans, as food can obtain iron from the pan during the cooking process.

64．Which of the following may be the title for the passage?

       A．Science, sports and exercise

       B．Correct iron deficiency

       C．Women, Iron and exercise

       D．Women, health and exercise

65．The third paragraph is developed mainly by             .

       A．organizing the details according to the order of time

       B．presenting the result followed by specific causes

       C．beginnign with details followed by a general statement

       D．making comparisons ad contrasts

66．What does it mean when you are in the third stage of iron defieiency?

       A．Nothing serious though you don’t have much iron stored in the body.

       B．There is not enough iron to form the molecules of blood protein to transport oxygen.

       C．The small blood vessels in your reet are beginnig to leak blood.

       D．No iron is ldft in your body and you would be in trouble without urgent measures.

67．What is the writer’s attitude in writing this passage?

       A．Defensive.       B．Persuasive.      C．Supportive.      D．Objective.

      Sports medicine experts have observed for  years that athletes such as long distance runners, especially women athletes, often display a lack of iron. Now a new study by a team of Purdue University researchers suggests that even moderate exercise may lead to reduced iron in the blood of women.

"We found that women who were normally inactive and then started a program of moderate exercise of middle degree showed sings of iron loss," says Roseanne M. Lyle, associate professor at Purdue. Her study of 62 formerly inactive women who began exercising three times a week for six months was published in the journal Medicine & Science in Sports & Exercise.

Iron deficiency is very common among women in general, affecting one in four female teenagers and one in five women aged 18 to 45, respectively. But the ratio is even greater among active women, affecting up to 80 percent of female endurance athletes. This means, Lyle says, that "too many women ignore the amount of iron they take in". Women of child-bearing age are at greatest risk, since their monthly bleeding is a major source of iron loss. Plus, many health-conscious women increase their risk by rejecting red meat, which contains the most easily absorbed form of iron. And because women often restrict their diet in an effort to control weight, they may not consume enough iron-rich food, and are liable to experience a deficiency.

Exercise can result in iron loss through a variety of mechanisms. Some iron is lost in sweat, and, for unknown reasons, intense endurance exercise is sometimes associated with bleeding of the digestive system. Athletes in high-impact sports such as running may also lose iron through a phenomenon where small blood vessels in the feet leak blood.

There are three stages of iron deficiency. The first and most common is having low iron reserves, a condition that typically has no symptoms. Fatigue and poor performance may begin to appear in the second stage of deficiency, when not enough iron is present to form the molecules(分子) of blood protein that transport oxygen to the working muscles. In the third and final stage, people often feel weak, tired, and out of breath - and exercise performance is severely compromised.

"People think that if they're not at the third stage, nothing is wrong, but that's not true," says John L. Beard, who helped design the Purdue study. "You're not stage 3 until your iron reserves go to zero, and if you wait until that point, you're in trouble."

       Beard and other experts say it’s advisable for people to have a yearly blood test. If iron levels are low, talk with a physician to see if the deficiency should be corrected by changing your diet and taking iron-rich foods or by taking iron-added pills.

 “Select breads and cereals with the words ‘iron-added’ on the label,” writes sports diet expert Nancy Clark. “This added iron supplements the small amount that naturally occurs in grains.” Clark also recommends cooking in iron pans, as food can obtain iron from the pan during the cooking process.

64．Which of the following may be the title for the passage?

       A．Science, sports and exercise

       B．Correct iron deficiency

       C．Women, Iron and exercise

       D．Women, health and exercise

65．The third paragraph is developed mainly by             .

       A．organizing the details according to the order of time

       B．presenting the result followed by specific causes

       C．beginnign with details followed by a general statement

       D．making comparisons ad contrasts

66．What does it mean when you are in the third stage of iron defieiency?

       A．Nothing serious though you don’t have much iron stored in the body.

       B．There is not enough iron to form the molecules of blood protein to transport oxygen.

       C．The small blood vessels in your reet are beginnig to leak blood.

       D．No iron is ldft in your body and you would be in trouble without urgent measures.

67．What is the writer’s attitude in writing this passage?

       A．Defensive.       B．Persuasive.      C．Supportive.      D．Objective.