To live forever was the dream of many emperors in ancient China.People were ordered to call them Wansui,which means 10,000 years,but no human could live that long.How long can humans really live? According to the latest scientific discovery,humans are able to live up to the age of 120 or perhaps even longer.
Several recent studies showed that our life span(壽命)can be extended(延長(zhǎng))far beyond normal limits.Cynthia Kenyon,a professor at the University of California in San Francisco doubled the life of a worm from two weeks to a month.By changing the function of a single gene,known as daf-2,the scientist not only added extra days to the worm’s life but also kept it a healthy as worms which were half its age.
There are two similar genes in the bodies of mammals.By changing the function of on gene,scientists extended the life of a mouse by 1 8 per cent(or 4.5 months).Another gene is called IGF-1.Researchers still don’t know how it affects our body.But by reducing its functions the life of a mouse increases by 33 per cent for 8.6 months).The average life span of a mouse is 26 months.
In the experiment of extending life,an ancient saying,“you are what you eat.” also seems to be true.Vegetables contain fewer calories than meat,and help to prolong life,scientists say. Research has found that taking in fewer calories affects our lives in a similar way to reducing IGF-1.
US biologist John Phelan suggests low calorie diets could increase human life span,but there is no proof yet.
Researchers are still waiting for the results of a study started in 1987.Monkeys are fed with low calorie food to see what happens.A monkey’s typical life span is 40 years,so there is a little while to wait.
In China,average,life expectancy(預(yù)期壽命)has now reached 70,double that of 1949. Increasing the length of our lives may bring us closer to the dreams of our ancient emperors.But it may also cause social problems such as housing and employment,social scientists have warned.
57.Which of the following is TRUE about statement of life span?
A.A few emperors in ancient China could live up to 10,000 years.
B.Creatures aren’t able to lives up to 120 years.
C.The dream of living forever is coming true.
D.In China,the average life span is twice as long as it was half a century ago.
58.What can we learn from paragraph 37
A.A mouse is able to live up to two years and a half.
B.A mouse can live for 34.6 months by reducing its gene.
C.Scientists are trying to work out how the IGF-1 gene affects our body.
D.The two similar genes have the same functions in the bodies of animals.
59.In paragraph 4,“you are what you eat,”probably means
A.the more you eat,the longer you will lives
B.the better you eat,the greater IGF-l’s functions are
C.the healthier food you eat,the healthier you are
D.the fewer calories you take,the happier life you’ll live
60.What is the main idea about this passage?
A.We are able to live longer.
B.The genes affect life span of human beings.
C.A balanced diet prolongs our life.
D.Extending life span has caused terrible social problems.
年級(jí) | 高中課程 | 年級(jí) | 初中課程 |
高一 | 高一免費(fèi)課程推薦! | 初一 | 初一免費(fèi)課程推薦! |
高二 | 高二免費(fèi)課程推薦! | 初二 | 初二免費(fèi)課程推薦! |
高三 | 高三免費(fèi)課程推薦! | 初三 | 初三免費(fèi)課程推薦! |
科目:高中英語(yǔ) 來(lái)源:2013年普通高等學(xué)校招生全國(guó)統(tǒng)一考試(天津卷)英語(yǔ) 題型:050
|
查看答案和解析>>
科目:高中英語(yǔ) 來(lái)源: 題型:閱讀理解
At a certain time in our lives we consider every place as the possible sites(地點(diǎn)) for a house. I have thus searched the country within a dozen miles of where I live. In imagination I have bought all the farms, one after another, and I knew their prices.
The nearest thing that I came to actual ownership was when I bought the Hollowell place. But before the owner completed the sale with me, his wife changed her mind and wished to keep it, and he offered me additional dollars to return the farm to him. However, I let him keep the additional dollars and sold him the farm for just what I gave for it.
The real attractiong of the Hollowell farm to me were its position, being about two miles from the village, half a mile from the nearest neighbor, bounded(相鄰) on one side by the river, and separated from the highway by a wide field. The poor condition fo the house and fences showed that it hadn’t been used for some time. I remembered from my earliest trip up the river that the house used to be hidden behind a forest area, and I was in a hurry to buy it before the owner finished getting out some rocks, cutting down the apples trees, and clearing away some young trees which had grown up in the fields. I wanted to buy it before he made any more of his improvements. But it turned out as I have said.
I was not really troubled by the loss. I had always had a garden, but I don’t thing I was ready for a large farm. I believe that as long as possible it is better to live free and uncommitted (無(wú)牽掛的). It makes but little difference whether you own a farm or not.
What do we know about the author?
A. He wanted to buy the oldest farm near where he lived.
B. He made a study of many farms before buying.
C. He made money by buying and selling farms.
D. He had the money to buy the best farm in the country.
Why did the author decide to buy the Hollowell place?
A. It was of good market value.
B. It was next to the highway.
C. It was in a good position.
D. It was behind a nice garden.
Why did the author want to buy the farm in a hurry?
A. He was afraid the owner might changes his mind.
B. He hoped to enlarge the forest on the farm.
C. He wanted to keep the farm as it was.
D. He was eager to become a farm owner.
The underlined words “the loss” in the last paragraph refer to ___.
A. the money the author lost in buying the farm
B. the sale of the garden in the Hollowell place
C. the removal of the trees around the house
D. the failure to possess the Hollowell place
What does the author believe as important in life?
A. To own a farm B. To satisfy his needs
C. To be free from worries D. To live in the countryside
查看答案和解析>>
科目:高中英語(yǔ) 來(lái)源:2008年普通高等學(xué)校招生全國(guó)統(tǒng)一考試四川卷英語(yǔ)試題 題型:閱讀理解
At a certain time in our lives we consider every place as the possible sites(地點(diǎn)) for a house. I have thus searched the country within a dozen miles of where I live. In imagination I have bought all the farms, one after another, and I knew their prices.
The nearest thing that I came to actual ownership was when I bought the Hollowell place. But before the owner completed the sale with me, his wife changed her mind and wished to keep it, and he offered me additional dollars to return the farm to him. However, I let him keep the additional dollars and sold him the farm for just what I gave for it.
The real attractiong of the Hollowell farm to me were its position, being about two miles from the village, half a mile from the nearest neighbor, bounded(相鄰) on one side by the river, and separated from the highway by a wide field. The poor condition fo the house and fences showed that it hadn’t been used for some time. I remembered from my earliest trip up the river that the house used to be hidden behind a forest area, and I was in a hurry to buy it before the owner finished getting out some rocks, cutting down the apples trees, and clearing away some young trees which had grown up in the fields. I wanted to buy it before he made any more of his improvements. But it turned out as I have said.
I was not really troubled by the loss. I had always had a garden, but I don’t thing I was ready for a large farm. I believe that as long as possible it is better to live free and uncommitted (無(wú)牽掛的). It makes but little difference whether you own a farm or not.
【小題1】What do we know about the author?
A.He wanted to buy the oldest farm near where he lived. |
B.He made a study of many farms before buying. |
C.He made money by buying and selling farms. |
D.He had the money to buy the best farm in the country. |
A.It was of good market value. |
B.It was next to the highway. |
C.It was in a good position. |
D.It was behind a nice garden. |
A.He was afraid the owner might changes his mind. |
B.He hoped to enlarge the forest on the farm. |
C.He wanted to keep the farm as it was. |
D.He was eager to become a farm owner. |
A.the money the author lost in buying the farm |
B.the sale of the garden in the Hollowell place |
C.the removal of the trees around the house |
D.the failure to possess the Hollowell place |
A.To own a farm | B.To satisfy his needs |
C.To be free from worries | D.To live in the countryside |
查看答案和解析>>
科目:高中英語(yǔ) 來(lái)源: 題型:閱讀理解
查看答案和解析>>
科目:高中英語(yǔ) 來(lái)源:四川省高考真題 題型:閱讀理解
查看答案和解析>>
百度致信 - 練習(xí)冊(cè)列表 - 試題列表
湖北省互聯(lián)網(wǎng)違法和不良信息舉報(bào)平臺(tái) | 網(wǎng)上有害信息舉報(bào)專區(qū) | 電信詐騙舉報(bào)專區(qū) | 涉歷史虛無(wú)主義有害信息舉報(bào)專區(qū) | 涉企侵權(quán)舉報(bào)專區(qū)
違法和不良信息舉報(bào)電話:027-86699610 舉報(bào)郵箱:58377363@163.com