Even if we have an extremely healthy diet and lifestyle, the human body is programmed to wear out at a maximum of about 120 years, and usually less. We all have a biological clock inside us which determines the moment when our organs cease to function properly. This is because our cells have stopped renewing themselves and our body can no longer repair itself. This is also the moment when we are more likely to begin to suffer from the diseases of old age such as arthritis and Alzheimer’s. However, rapid advances in DNA research are beginning to throw light on the secrets of the ageing process. By the end of this century we could literally have the power of life over death.
Although it has long been accepted that humans have a fixed lifespan, it is also a fact that certain other organisms, such as reptiles and amphibians, appear to live indefinitely. The only reason we do not see 500-year-old alligators is because in the wild their lives are always in danger, from man, from pollution and from other animals. When they are kept in zoos they do not seem to age at all after they are fully grown. The same is true of some species of fish, which grow indefinitely and show no signs of ageing. The existence of animals with no fixed lifespan seems to indicate that an age gene really does exist. It is this gene which scientists are searching for, which may delay or repair damage to the body caused by ageing.
Another new area of research involves the oxidation（氧化） theory, which says that ageing is caused by the same process that makes iron rust. In controlled experiments, the lifespans of certain animals were shown to be lengthened with anti-oxidants; for example, the lifespan of mice can be increased by 30%. Antioxidants are already being used in face creams and other cosmetics, and they are likely to play an important part in keeping people physically young.
Perhaps the most immediate advance we are likely to see in the battle to halt（停止）the ageing process will be organ replacement. By the year 2020 it is likely that we will be replacing injured bones or even organs like livers and kidneys with ones “grown” in laboratories. By 2050 perhaps every organ in the body, except the brain, will have become commercially available. Recent experiments also show that it may one day be possible to “grow” new organs inside our body to replace worn-out ones, something which lizards and alligators already do.
Suddenly immortality（不死，不朽） seems within reach. We can begin to imagine a future where we are born, we grow to maturity, but we never grow old and die. But do we really want to live forever?
【小题1】 When all humans reach a certain age,         .

Even if we have an extremely healthy diet and lifestyle, the human body is programmed to wear out at a maximum of about 120 years, and usually less. We all have a biological clock inside us which determines the moment when our organs cease to function properly. This is because our cells have stopped renewing themselves and our body can no longer repair itself. This is also the moment when we are more likely to begin to suffer from the diseases of old age such as arthritis and Alzheimer’s. However, rapid advances in DNA research are beginning to throw light on the secrets of the ageing process. By the end of this century we could literally have the power of life over death.

Although it has long been accepted that humans have a fixed lifespan, it is also a fact that certain other organisms, such as reptiles and amphibians, appear to live indefinitely. The only reason we do not see 500-year-old alligators is because in the wild their lives are always in danger, from man, from pollution and from other animals. When they are kept in zoos they do not seem to age at all after they are fully grown. The same is true of some species of fish, which grow indefinitely and show no signs of ageing. The existence of animals with no fixed lifespan seems to indicate that an age gene really does exist. It is this gene which scientists are searching for, which may delay or repair damage to the body caused by ageing.

Another new area of research involves the oxidation（氧化） theory, which says that ageing is caused by the same process that makes iron rust. In controlled experiments, the lifespans of certain animals were shown to be lengthened with anti-oxidants; for example, the lifespan of mice can be increased by 30%. Antioxidants are already being used in face creams and other cosmetics, and they are likely to play an important part in keeping people physically young.

Perhaps the most immediate advance we are likely to see in the battle to halt（停止）the ageing process will be organ replacement. By the year 2020 it is likely that we will be replacing injured bones or even organs like livers and kidneys with ones “grown” in laboratories. By 2050 perhaps every organ in the body, except the brain, will have become commercially available. Recent experiments also show that it may one day be possible to “grow” new organs inside our body to replace worn-out ones, something which lizards and alligators already do.

Suddenly immortality（不死，不朽） seems within reach. We can begin to imagine a future where we are born, we grow to maturity, but we never grow old and die. But do we really want to live forever?

1. When all humans reach a certain age,         .

A．they suffer the effects of their diet and lifestyle

B．the organs stop to perform appropriately

C．their cells continue to renew themselves

D．they develop arthritis and Alzheimer’s

2. The purpose of showing the case of alligators is to prove         .

A．alligators are in danger in the wild because of the threat from man, pollution and other animals

B．it is widely accepted that humans have a fixed lifespan

C．there exists an age gene which may control ageing

D．the age gene damages the body

3.The underlined phrase “live indefinitely” in Paragraph 2 probably mean         .

A．live for a period of time without a fixed end

B．live without a clear aim

C．live in an uncertain way

D．live without being fully grown

4.It can be inferred from Paragraph 4 that         .

A．by 2050 we might have most of our worn-out organs replaced with new ones commercially

B．never can the ageing process be avoided

C．livers and kidneys are sure to be grown in laboratories by the year 2020

D．lizards and alligators grow new organs inside their body to replace worn-out ones

5. What is the main topic of this passage?

A．DNA researches show how our cells renew themselves.

B．Anti-oxidants are likely to play an important part in keeping people young.

C．How our biological clock works?

D．Eternal（永恒的） youth: new developments in anti-ageing research.

6.By saying “But do we really want to live forever”, the author may probably mean         .

A．a future where we are born, we grow to maturity, but we never grow old and die is on its way

B．he is uncertain whether we can live forever

C．it remains to be seen whether immortality is a blessing or a curse

D．immortality is no longer a dream

In a class I teach for adults, I recently did the “unpardonable.” I gave the class homework!

The assignment (任务) was to “go to someone you love 　36 the next week and tell them you love them. It 　37 to be someone you have never 　38 those words to before or at least haven’t shared those words with for a long time.” That doesn’t 　39 like a very tough assignment, 　40 you stop to realize that most of the men were over 35 and were 　41 in the generation of men that were taught that expressing emotions is not “macho (男子汉气概的).” Showing feelings or crying (heaven forbid!) was just not done 　42 this was a very threatening assignment for some.

At the 　43 of our next class, I asked if someone wanted to 　44 what happened when they told someone they loved them. I fully expected one of the 　45 to volunteer, as was usually the 　46 , but on this evening one of the men raised his hand. He appeared quite moved and a bit 　47 . As he unfolded out of his chair, he began by saying, “Dennis. I was quite 　48 with you last week when you gave us the assignment. I didn’t feel that I had 　49 to say those words to and 　50 , who were you to tell me to do something that personal? But as I began driving home my conscience (良知) started talking to me. It was telling me that I 　51 exactly who I needed to say I love you to. You see, five years ago, my father and I had a heated 　52 and really never resolved it since that one. We 　53 seeing each other unless we absolutely had to at Christmas or other family gatherings. But 　54 then, we hardly spoke to each other. So last. Tuesday 　55 I got home, I had convinced myself. I was going to tell my father I loved him.”

36．A．after　　　　　　　　　 B．before　　　　　　　　 C．for　　　　　　　　　　 D．within

37．A．has to　　　　　　　　 B．ought to　　　　　　 C．had better　　　　　 D．can

38．A．told　　　　　　　　　　 B．said　　　　　　　　　　 C．talked　　　　　　　　 D．spoken

39．A．look　　　　　　　　　 B．hear　　　　　　　　　 C．listen　　　　　　　　　 D．sound

40．A．when　　　　　　　　 B．until　　　　　　　　　 C．that　　　　　　　　　　 D．unless

41．A．born　　　　　　　　　 B．grown　　　　　　　　 C．raised　　　　　　　　 D．risen

42．A．And　　　　　　　　　 B．But　　　　　　　　　　 C．So　　　　　　　　　　 D．For

43．A．beginning　　　　　 B．end　　　　　　　　　　 C．middle　　　　　　　　 D．stating

44．A．announce　　　　　 B．share　　　　　　　　　 C．answer　　　　　　　 D．ask

45．A．men　　　　　　　　　 B．adults　　　　　　　　 C．students　　　　　　 D．women

46．A．case　　　　　　　　　 B．thing　　　　　　　　　 C．story　　　　　　　　　 D．experience

47．A．afraid　　　　　　　　 B．shaken　　　　　　　 C．terrible　　　　　　　 D．worried

48．A．happy　　　　　　　　 B．pleased　　　　　　　 C．angry　　　　　　　　 D．satisfied

49．A．everybody　　　　　 B．nobody　　　　　　　 C．someone　　　　　　 D．anyone

50．A．else　　　　　　　　　　 B．except　　　　　　　　 C．beside　　　　　　　　 D．besides

51．A．thought　　　　　　　 B．considered　　　　　 C．knew　　　　　　　　 D．guessed

52．A．disagreement　　　 B．encouragement　　 C．disappointment　　 D．discouragement

53．A．imagined　　　　　　 B．risked　　　　　　　　 C．avoided　　　　　　　 D．escaped

54．A．still　　　　　　　　　　 B．even　　　　　　　　　 C．just　　　　　　　　　　 D．only

55．A．by the time　　　　 B．at the time　　　　　 C．for the time　　　　 D．during the time

The amount of water in the world is finite(有限的). The number of people is growing fast and water use is growing even faster. Global water consumption rose six times between 1900 and 1995—more than double the rate of population growth.

As important as quantity is quality—with pollution increasing in some areas，the amount of useable water declines.

And the wider effects of water shortages are just as frightening as the prospect of having too little to drink.

Seventy percent of the water used worldwide is used for agriculture. Much more will be needed if we are to feed the world's growing population. And consumption will rise further as more people expect Western－style lifestyles and diets—one kilogram of grain－fed beef needs at least 15 cubic metres of water，while a kilo of cereals(谷物)needs only up to three cubic metres.

New technology can help，however，especially by cleaning up pollution and so making more water useable，and in agriculture，where water use can be made far more efficient.

Drought－resistant(抗旱的)plants can also help.

The optimists say“virtual water”may save the day—the water contained in crops which could be exported from water－rich countries to dry ones. But the amounts involved would be huge，and the energy needed to transport the water would be enormous(巨大的).

In any case，it is not just us who need water，but every other species that shares the planet with us. We have to rethink how much water we really need if we are to learn how to share the earth's supply. While dams and other large－scale schemes play a big role worldwide，there is also a growing recognition of the value of using the water we already have more efficiently rather than harvesting ever more from our rivers. For millions of people around the world，getting it right is a matter of life and death.

1. Which of the following statements on water consumption is NOT true?

A. Agriculture consumes more than haft of the water used in the world.

B. The growing population worsens the water shortage situation.

C. Lifestyles play an important role in water consumption.

D. The Western way of agriculture uses more water than the Asian way.

2. “Virtual water” refers to the water that ________.

A. is hidden in crops

B. is saved in agriculture

C. can be transported

D. can be reused with the aid of the Internet

3. In the last paragraph，the author mainly ________.

A. criticizes big projects such as dams

B. criticizes the use of river water

C. calls for the protection of other species

D. calls for the more efficient use of water

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

A. Water is mainly wasted in agriculture.

B. Water pollution is threatening our health.

C. Shortage of water is a very serious problem.

D. Population growing influences water use.