When people lose legs after accidents or illnesses, emergency care and artificia
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When people lose legs after accidents or illnesses, emergency care and artificial limbs（假肢）often allow them to walk again. Newts （蝾螈） in the same situation, on the other hand, can grow limbs back on their own! Scientists have known for a long time that certain animals can re-grow limbs, but they haven’t quite figured out how these creatures do it.
Researchers have now come up with some new ideas. Their work may give people the ability to re-grow lost limbs. The researchers started with two simple experiments：when you cut a newt’s leg at the ankle, only the foot grows back；when you cut off a leg at the very end, the whole leg grows back. In both cases, the re-growth begins with stem cells. Stem cells can develop into nearly any type of cell in the body.
How do a newt’s stem cells know when to grow only a foot and when to re-grow a whole leg?
This question relates to another mystery. In newt’s, a cut-off leg will grow back only if the nerve bundle（神经束）in it also grows back , but if something prevents the nerve bundle from growing, the stem cells at the wound won’t re-grow a new leg.
In its study, a British team focused on a protein called n-AG. When the team prevented nerves in a limb from growing, but added the n-AG protein to stem cells in the limb, the limb still re-grew. That protein seems to guide limb re-growth. People have proteins that are similar to n-AG. Further research into these materials may someday help human limbs recover by themselves.
40. In the experiments, the researchers cut off a newt’s foot or leg to find out _____.
A. what stem cells were B. whether they would grow back
C. how long it would take to re-grow D. how they would re-grow
41. A newt will re-grow its leg if _____.
A. its ankle was cut off but the nerve bundle was good
B. its leg was cut off and the nerve bundle stopped growing
C. its leg was cut off and the nerve bundle could grow back
D. its ankle and the nerve bundle were cut off
42. What do the underlined words “these materials” refer to?
A. Nerve bundles and proteins. B. Proteins similar to n-AG.
C. Stem cells and proteins. D. Stem cells and nerve bundles.
43. The first sentence of the passage _____.
A. acts as a lead–in B. shows where researchers got their new ideas
C. states the author’s opinion D. describes the result of researchers’ studies |
答案
| 40-43 DCBA |
解析
| 略 |
举一反三
B
Do you have a sore throat, a running nose and a headache? Do you keep coughing and sneezing? If you do, the chances are that you have a cold or perhaps flu — but which one? Although both colds and flu are caused by viruses, they are very different illnesses.
Colds, which usually last about a week, affect the nose most. They commonly cause a running nose and sneezing. Sometimes, they cause a headache, a cough and slightly aching muscles.
Flu is a much more serious illness and is caused by different group of viruses. People with flu usually get all the symptoms described above. However, they also get a high fever, a dry cough and much worse aching. Fever is one of the characteristic symptoms of the flu for all ages. The symptoms also last much longer. Sometimes they don’t disappear for at least two weeks.
Flu can be a deadly disease. The elderly, who are weaker and less healthy than most younger people, can die from flu. This is one reason why old people are advised to have a flu injection (预防针) before the start of winter when flu is most common. This injection is inexpensive and definitely worth it.
If you have a cold or flu, you must always deal with used tissues (纸巾)carefully. Don’t leave dirty tissues on your desk or on the floor. Someone else has to pick these up and viruses could be passed on. And finally, remember to cover your nose and mouth when you sneeze! You don’t want to see the small drop of liquids blown out of your nose and mouth when you sneeze, do you? Disgusting, eh? Now you can understand why it’s a good idea to cover your nose and mouth when you sneeze!
60. According to the passage, people with colds hardly get _______.
A. a headache B. a high fever C. a running nose D. aching muscles
61. In paragraph 4, we learn that _______.
A. flu injection can cause death B. most old people die from flu
C. flu is most common in summer D. flu can kill old people easily
62. Dealing with used tissues properly is important because _______.
A. it helps keep your classroom tidy B. people hate picking up dirty tissues
C. it prevents the spread of colds and flu D. picking up lots of tissues is hard work
63. Which of the following statements is true according to the passage?
A. Both colds and flu last the same time.
B. Both colds and flu can be prevented by injection.
C. Both colds and flu are caused by the same viruses.
D. Both colds and flu have an aching symptom. |
As AH1N1 flu continues to spread, experts from the World Health
Organization are calling for everyone to practice smart flu prevention
techniques. Besides washing your hands and getting enough sleep,
here are the other 7 ways to keep your body strong and your immune
(免疫) system ready to fight infection.
Avoid Contact with Sick PeopleFlu virus is spread when particles (微粒) blown into the air through a cough or sneeze reach someone else’s nose. So if you’re coughing or sneezing, cover your mouth and then wash your hands, and if you have to be around someone who is sick, try to stay a few feet away from them and avoid physical contact.
Eat Immune – Boosting Foods
Keeping your body strong and ready to fight infection is important in flu prevention. Fatty foods can make you feel lazy, and make your immune system working in an inactive and compromised way. So stick with wholes grains, colorful vegetables, and vitamin – rich fruits.
Avoid Alcohol
In addition to being a mood calm and pleasant, alcohol is an immune restriction that can actually decrease your resistance to virus infections like AH1N1flu. So avoid alcohol to keep your immune system strong.
Drink Enough Water
Drink 8 – 10 glasses of water each day to wash out poisonous things from your system and maintain system in a good state,
Keep Physically Active
Adequate exercise – for example walking for 30 to 40 minutes 3 or 4 times a week – supports the immune system by increasing circulation, speeding the body’s oxygen – taking – in, taking away poisonous things through sweat, and releasing tension and stress. So get moving!
Be Careful of Surfaces
This is as much a mindfulness exercise as anything else. Be aware of what public surfaces you touch, when you’ve shaken hands with someone, or when you’re using something like a pen that others have recently used – and don’t touch your face until you’ve had a chance to wash your hands.
Know When to Get Help
AH1N1 flu can look like regular flu, so don’t feel like you necessarily are infected if you’re exhibiting flu – like symptoms. But do consult your doctor if your symptoms are severe.
64．Which of the following pictures is talked about in the passage?
65．How can fatty foods affect a person? .
A．They cause human’s immune system inactive
B．They help to keep one’s body strong
C．They are good for fighting infection
D．They are favorable for a calm mood
66．Drinking water and having enough exercise play the similar role in .
A．increasing circulation B．taking in more oxygen
C．cleaning your system D．reducing your pressure
67．What does the author strongly suggest in the last paragraph?
A．Don’t touch your face! B．Avoid using others’ pen!
C．Don’t fear getting infected! D．See a doctor if you’re seriously ill! |
D
If you want to live longer and lower the risk of heart disease, a move to the mountains may help． Research by scientists in Greece shows that living in the mountains is good for the heart and longevity． People living at higher altitude have lower possibility of dying from heart disease than those closer to sea level, even if they have factors that could increase their risk．"Residence in mountainous areas seems to have a "protective effect" from heart disease," said Dr Nikos Baibas of the University of Athens．He and his colleagues suspect that the increased exercise from walking up mountainous area gives the heart a good workout and enables it to cope with lower levels of oxygen．
Researchers studied the health records and death rates of 1,150 Greeks who lived in three villages near Athens over 15 years．One village was 1,000 metres above sea level and the other two were in low-lying areas．Although men and women living in the mountainous village had higher blood pressure rates and other risk factors than people in the other villages, they had a lower rate of death from heart disease and other causes after a fifteen year follow-up．"The contrast was more evident among men than among women," Baibas added in a report in the Journal of Epidemiology and Community Health．Heart disease is one of the world"s top killers．Smoking, high blood pressure, raised cholesterol levels, being overweight or obese and a family history of the illness increase the odds of developing the disease．
68．The first sentence in the passage is used to __________．
A．tell readers what the passage focuses on
B．give a very good guessing
C．warn people of the risk of heart disease
D．name a new unknown illness
69．According to the passage, a person _________ may have less possibility of having heart attack.
A．with more money B．with a better living habit
C．from higher altitude D．in a happier mood
70．How long does the research of the Greeks last?
A．At most 10 years． B．About 15 years．
C．More than 20 years． D．Not mentioned．
71．Apart from altitude, how many factors raise the chance of developing heart disease?
A．three B．Four C．Five D．Six |
Do you like sports? If your answer is yes, sometimes you will find it very difficult to have enough time to do it even if it’s on weekends. However, you don’t have to worry now because of a “sunshine sports” program launched (启动) by the Ministry of Education.
It suggests students around the country have an hour of sports every day. The difference is that students will be able to do any sport they please. The idea is to make students happy and keep them healthy at the same time.
Han Jiawen likes the idea. The 13-year-old studies in Shanghai Yangsi Middle School. Her school began the activity at the beginning of the term. Han an her classmates skipped rope together. “We had a good time,” said Han. “It was better playing than having classes.”
Wang Lichao welcomes the idea, too. “It’s good to be able to breathe some fresh air instead of sitting in the classroom.”
But the 14-year-old from Tianjin wonders whether there will be enough space for everyone. “With so many students outside,” he said, “I’m afraid there won’t be enough standing room in the playground.”
Wu Jiatong’s school in Liaoning already has something like a “sunshine sports” program. From the beginning of this term, Wu and other students at her school have been jogging for 40 minutes every morning. “It’s tiring,” said Wu. “But we do feel healthier.” “We hope we can do what we want. The school says later we can have rope skipping or kicking jianzi. I can’t wait!” she said.
What about your school? There must be more sports that interest you and your schoolmates.
56. According to the author, which of the following allows the students to have enough time to do sports?
A. The headmaster. B. A teacher.
C. A TV program. D. A program called “sunshine sports”.
57. What does Han Jiawen think of the “sunshine sports” program?
A. It’s useless. B. It’s wonderful. C. It’s healthy. D. It’s tiring.
58. According to the passage, Wu Jiatong ________.
A. hates her school program--- jogging
B. doesn’t like sitting in the classroom
C. wants to do different kinds of sports
D. complains there isn’t enough room to do sports
59. Which of the following statements is true?
A. All the students think it easy to carry out the program.
B. The program allows students to have an hour of sports on weekends.
C. Wang Lichao thinks sitting in the classroom is better than playing.
D. There may be not enough room for every student to do sports in some schools. |
Cancer researchers urged people on Wednesday to take more vitamin D to lower risk of cancer, saying studies showed a clear link. “Our suggestion is for people to increase their intake (吸入，摄入), through diet or a vitamin supplement,” Dr. Cedric Garland said in a telephone interview.
Garland"s research team reviewed 63 studies, including several large long-term ones, on the relationship between vitamin D and certain types of cancer worldwide between 1966 and 2004. “There"s nothing that has this ability to prevent cancer,” he said, urging governments and public health officials to do more to fortify (增强) foods with vitamin D. Garland is part of a University of California at San Diego Moores Cancer Center team that published its findings this week online in the American Journal of Public Health. Vitamin D is found in milk, as well as in some fortified orange juice, yogurt and cheeses, usually at around 100 international units（IU）a serving. “People might want to consider a vitamin supplement to raise their intake to 1000 IUs per day” Garland said， adding that it was well within the safety guidelines established by the National Academy of Sciences.
The authors said that taking more vitamin D could be especially important for people living in northern areas, which receive less vitamin D from sunshine.
“African Americans, who don"t produce as much of the vitamin because of their skin colour, could also benefit significantly from a higher intake,” the authors said.
61. According to the passage, people are advised to take more Vitamin D, because__.
A. it is nutritious B. it can‘t harm people’s health
C. it can lower cancer risk D. it is not taken enough every day
62. Which of the following can not help people get more Vitamin D?
A. Have some sunshine B. Have more meat
C. Have more fortified cheese D. Have a vitamin supplement
63.Who can Garland probably be?
A. A health researcher B. A doctor
C. A scientist D. A public health official
64.Which of the following food can lower people‘s chance of getting cancer?
A. Milk B. Fortified orange juice
C. Fortified yogurt D. All of the above
65.People from which area should take more Vitamin D according to the passage?
A. Asian people B. African people
C. American people D. European people |
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