There are new findings that not enough sleep ...

There are new findings that not enough sleep may cause people to gain weight. Researchers say a lack of sleep can produce hormonal(激素的) changes that increase feelings of hunger.

In one study, researchers in the United States examined information on more than 1000 people. The people had taken part in a long-term study of sleep disorders.

Some people slept less than five hours a night. They had 15 percent higher blood levels of a hormone called ghrelin than people who slept eight hours. And they had 15 percent less of the hormone leptin. Experts say ghrelin helps make people feel hungry; leptin makes you feel full.

The scientists say these hormonal changes may be a cause of obesity in Western societies. They note the combination that sleep limitation is common and food is widely available.

The results were not affected by how much people exercised. People who are awake longer have more time to burn energy. But the researchers say loss of sleep may increase hunger especially for high-calorie foods, so people gain weight. It seems that, for survival, the body may be designed to store more fat during times with less sleep.

Researchers from Stanford University in California and the University of Wisconsin did the study. They found that the best amount of sleep for weight control is 7.7 hours a night.The Public Library of Science published the findings in its journal Medicine . Internet users can read the full study, free of charge, at plos. org.

1.Not enough sleep can cause obesity by ______.

A. burning more of your energy

B. making you want to eat more food

C. keeping you from doing exercise

D. helping you feel great without food

2.When you sleep 7.7 hours a night, you will ______ .

A. have your ghrelin level rise and leptin level drop

B.have your leptin level rise and ghrelin level drop

C.have your ghretin and leptin levels properly balanced

D.have your hunger increase and your weight decrease

3.You can read the findings________

A. Only on the Internet

B. only in Medicine

C. Both on the Internet and in Medicine

D. Neither on the Internet nor in Medicine

高三英语阅读理解中等难度题查看答案及解析

A new study warns that about thirty percent of the world's people may not have enough water by the year 2025.

A private American organization called Population Action International did the new study. It says more than three-hundred-thirty-five-million people lack enough water now. The people live in twenty-eight countries. Most of the countries are in Africa or the Middle East.

P-A-I researcher Robert Engelman says by the year 2025, about three-thousand-million people may lack water. At least 18 more countries are expected to have severe water problems. The demand for water keeps increasing. Yet the amount of water on Earth stays the same.

Mr. Engelman says the population in countries that lack water is growing faster than in other parts of the world. He says population growth in these countries will continue to increase.

The report says lack of water in the future may result in several problems. It may increase health problems. Lack of water often means drinking waters not safe. Mr. Engelman says there are problems all over the world because of diseases, such as cholera, which are carried in water. Lack of water may also result in more international conflict. Countries may have to compete for water in the future. Some countries now get sixty percent of their fresh water from other countries. This is true of Egypt, the Netherlands, Cambodia, Syria, Sudan, and Iraq. And the report says lack of water would affect the ability of developing to improve their economies. This is because new industries often need a large amount of water when they are beginning.

The Population Action International study gives several solutions to the water problem. One way, it says, is to find ways to use water for more than one purpose. Another way is to teach people to be careful not to waste water. A third way is to use less water of agriculture.

The report also says long-term solutions to the water problem must include controls on population growth. It says countries cannot provide clean water unless they slow population growth by limiting the number of children people have.

1. 　　　　　　 are expected to have severe water problems by the year 2025.

A. 46 countries　　　　 B. 18 countries

C. 28 countries　　　　 D. No countries

2. All the following are true except　　　　　　　　 .

A. Lack of water may cause conflict between countries

B. New industries need a lot of water

C. There are solutions to the water problem

D. Egypt now has enough fresh water

3..What can be inferred from the passage?　　　 .

A. There is connection between providing clean water and slowing population growth

B. Lack of water may also result from international conflict

C. The ability of developing has nothing to do with lack of water

D. It is not known whether diseases have something to do with lack of water

4.The best title of the passage would be 　　　　　　 .

A. World Conflict　　　　　　 B. World Water Shortage

C. Diseases and Water　　　　 D. Population and Water

高三英语阅读理解中等难度题查看答案及解析

Sometimes we may find that every week there are a lot of new stories about how climate change is affecting the planet, or new plans to battle its effects like the one announced by President Barack Obama the other day. But the concept itself isn't new at all --- in fact, scientists have been exploring questions about climate change for almost 200 year.

The idea of “greenhouse gases” goes back to 1824, when Joseph Fourier wondered what was regulating the earth's temperature. Fourier concluded that the atmosphere must be responsible for containing the heat absorbed from the sun and described it as a box with a glass lid: As light shines through the glass, the inside gets warmer as the lid traps the heat. As Fourier's ideas spread, it came to be called “the greenhouse effect”.

Scientists continued to study the greenhouse effect. Until a Swedish chemist named Svante Arrhenius came along, scientists understood how global warming actually works. After years of work, Arrhenius determined that the level of carbon dioxide in the atmosphere did in fact have a direct effect on global temperatures.

Arrhenius found that CO2, and other gases trap radiation, which warms the atmosphere. Arrhenius was the first to suspect that burning coal could contribute to the greenhouse effect. But Arrhenius welcomed the warming effect on the planet. At a lecture later that year, Arrhenius noted that creatures of a warmer earth “might live under a milder sky and in less barren surroundings”.

While Arrhenius' findings won him the 1903 Nobel Prize in chemistry, scientists kept debating whether the greenhouse effect was increasing until 1950, when researchers finally began to find strong data supporting it. By the end of the 1950s, American scientists had been sounding the alarm on the long-term consequences of climate change. Climate change research has come a long way since Fourier first described the greenhouse effect – still, maybe Arrhenius should have been more careful of what he wished for.

1.What can we know from Paragraph 1?

A. Climate change has caused terrible disasters.

B. The topic of climate change has been talked a lot.

C. Scientists should work harder to research climate change.

D. The whole world should cooperate to protect the environment.

2.What does the underlined word “it” in Paragraph 2 refer to?

A. The atmosphere.

B. The idea.

C. The earth.

D. The earth's temperature.

3.What's the main idea of Paragraph 3?

A. Serious consequences of climate change.

B. The history of studying the greenhouse effect.

C. Significant research findings about climate change.

D. Scientists' doubts about the cause of global warming.

4.What did Arr henius think of the greenhouse effect?

A. It was beneficial for creatures on the earth.

B. It was totally responsible for climate change

C. It brought more troubles than benefits to human beings.

D. It worked as a punishment for human harmful activities.

5.What's the author's attitude towards Arr henius' expectation?

A. Cautious.　　 B. Defensive.　　 C. Positive.　　 D. Negative.

高三英语阅读理解中等难度题查看答案及解析

Sometimes we may find that every week there are a lot of new stories about how climate change is affecting the planet, or new plans to battle its effects. But the concept itself isn’t new at all — in fact, scientists have been exploring questions about climate change for almost 200 years.

The idea of ''greenhouse gases'' goes back to 1824, when Joseph Fourier wondered what was regulating the earth's temperature. Fourier concluded that the atmosphere must be responsible for containing the heat absorbed from the sun and described it as a box with a glass lid: As light shines through the glass, the inside gets warmer as the lid traps the heat. As Fourier's ideas spread, it came to be called ''the greenhouse effect''.

Scientists continued to study the greenhouse effect. Not until a Swedish chemist named Svante Arrhenius came along, did scientists understand how global warming actually works. After years of work, Arrhenius determined that the level of carbon dioxide in the atmosphere did in fact have a direct effect on global temperatures.

Arrhenius found that CO2, and other gases trap radiation, which warms the atmosphere. Arrhenius was the first to suspect that burning coal could contribute to the greenhouse effect. But Arrhenius welcomed the warming effect on the planet. At a lecture later that year, Arrhenius noted that creatures of a warmer earth ''might live under a milder sky and in less barren surroundings''.

While Arrhenius' findings won him the 1903 Nobel Prize in chemistry, scientists kept debating whether the greenhouse effect was increasing until 1950, when researchers finally began to find strong data supporting it. By the end of the 1950s, American scientists had been sounding the alarm on the long-term consequences of climate change. Climate change research has come a long way since Fourier first described the greenhouse effect — still, maybe Arrhenius should have been more careful of what he wished for.

1.What does the underlined word ''it'' in Paragraph 2 refer to?

A.The climate change. B.The greenhouse effect.

C.The atmosphere. D.The heat from the sun.

2.When did the scientists first find evidence for the bad effect of global warming?

A.In 1824. B.In 1903.

C.In 1950. D.200 years ago.

3.What's the author's attitude towards Arrhenius' wish?

A.Optimistic. B.Negative.

C.Neutral. D.Ambiguous.

4.What's the main idea of the text?

A.Causes of climate change. B.Effects of greenhouse gases.

C.Findings about global warming. D.Explorations on climate change.

高三英语阅读理解中等难度题查看答案及解析

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？

高三英语阅读理解中等难度题查看答案及解析

HOW TO GET MORE SLEEP

Many studies warn that not having enough sleep may lead to serious health problems, affecting our daily life, work and study. You’ve probably known this for long, yet you still don’t get a full night sleep due to an incredible work schedule. So what can you do to make more time for sleep, and get a better night’s rest overall?

• Invest in a better-quality mattress. If you’re sleeping on a years-old, worn-out mattress(床垫), it’s no wonder why you wake up feeling tired in the morning. 1. With a new mattress that’s better suited to your sleeping habits, you’ll get to sleep faster and stay asleep consistently.

• 2. There are many habits that can affect how much sleep you get, including how much caffeine you consume throughout the day (and when you consume it — even a few hours before bedtime can interfere with sleep), whether or not you physically exercise, and how long you spend staring at a digital screen before bed.

• Take a closer look at your schedule.3. In Western culture, there’s a lot of pressure to fill up our schedules to seem important and socially integrated, so your daily activities might have some faults or unnecessary tasks that can be skipped or delayed. 4.

Sleep is even more important than you probably realized, but it’s entirely within your power to reshape your sleeping habits for good. Make sleep your first priority, scheduling time for it the way you’d schedule a meeting, and work the rest of your schedule around it. 5.

A.Watch your habits.

B.Some habits contribute to a good night’s sleep.

C.Without enough sleep, you could take more risks in your life.

D.A new mattress can be a big investment, but it’s almost worth the money.

E.Draw a line between professional and personal time, and make sleep a higher priority.

F.If you feel like you’re too busy to sleep, consider taking a second look at your schedule.

G.In time, it will become the new routine, and you’ll improve your health and productivity.

高三英语七选五中等难度题查看答案及解析

The food she has prepared for the party is not enough, for there are _____people than she expected．

高三英语单项填空中等难度题查看答案及解析

The food she has prepared for the party is not enough, for there are ______ people than she expected．

A. so many　　 　　　　　　　　　 　 B. fewer　　 　　　　　　　　　 　 C. many more　 　　　　　　　　　 D. much more

高三英语单项填空中等难度题查看答案及解析

The food she has prepared for the party is not enough, for there are ______ people than she expected．

A. so many　　 　　　　　　　　　 　 B. fewer　　 　　　　　　　　　 　 C. many more　 　　　　　　　　　 D. much more

高三英语单项填空中等难度题查看答案及解析

The food she has prepared for the party is not enough, for there are _____people than she expected．

A．so many B．so much C．many more D．much more

高三英语单项填空中等难度题查看答案及解析