第三篇

eat more，weigh less，live longer

    clever genetic detective work may have found out the reason why a near。starvation diet

 prolongs the life of many animals．    ‘

    ronald kahn at harvard medical school in boston，us，and his colleagues have been able

to extend the lifespan(寿命)of mice by 18 per cent by blocking the rodent’s(啮齿动物)

increase of fat in specific cells．this suggests that thinness--and hot necessarily diet—-promotes long life in “ calerie (热量卡) restricted” animals．

    “it’s very cool work．”says aging researcher cynthia kenyon of the university of california，san francisco．“these mice eat all they want，lose weight and live longer．it’s like heaven．”

    calorie restriction dramatically extends the lifespan of organisms as different as worms and rodents．whether this works in humans is still unknown，partly because few people are willing to submit to such a strict diet．

    but many researchers hope they will be able to trigger the same effect with a drug once

they understand how less food leads to a longer life．one theory is that eating less reduces the increase of harmful things that can damage cells．but kahn’s team wondered whether the

 animals simply benefit by becoming thin．

    to find out。they used biology tricks to disrupt the insulin(胰岛素)receptor(受体)gene in lab mice—_but only in their fat cells．“since insulin is needed to help fat cells store fat，these animals were protected against becoming fat，”explains kahn．

    this slight genetic change in a single tissue had dramatic effects．by three months of age，kahn，s modified mice had up to 70 per cent less body fat than normal control mice，despite the fact that they ate 55per cent more food per gram of body weight．

    in addition，their lifespan increased．the average control mouse lived 753 days，while the thin rodents averaged a lifespan of 887 days．after three years，all the control mice had died，but one--quarter of the modified rodents were still alive．

    “that they get these effects by just manipulating t11e fat cells is controversial，”says

 leonard guarente of the massachusetts institute of technology, who studies calorie restriction and aging．

．   but guarente says kahn has yet to prove that the same effect is responsible for increased

 lifespan in calorie．res

       

tricted animals．“it might be the same effect or there might be two routes to long life，”he points out，“and that would be very interesting．” 

 

41 ronald kahn and his colleagues can make mice live longer by

  a offering them less food．

  b giving them a balanced diet．

  c disrupting the specific genes in their fat cells．

  d preventing them growing larger

 

42 according to t11e passage，we d0 not know whether humans will benefit from taking in fewer calories partly because

  a humans，worms and rodents are different．

  b most people are not willing to be put on a strict diet．

  c the effect is not known．

  d genetic changes in tissues can not be performed on humans

 

43 what does the last sentence in the third paragraph imply?

    a people like to lose weight，but they do not like to eat less．

    b people want to go to heaven．but they do not want to die．

    c  mice will go to heaven if they lose weight．

d  mice enjoy losing weight．

 

44 the average modified mouse lived

    a  3 years．

    b  753 days．

    c  more than 3 years．

d 887 days．

 

45 what can be inferred from the passage about the route to long life?

  a  it remains to be studied．

&nb

         

sp; b  it has already been discovered．

  c  eating more leads to long life．

  d  eating less leads to long life．

 

第5部分：补全短文  (第46～50题，每题2分，共10分)

    阅读下面的短文，文章中有5处空白，文章后面有6组文字，请根据文章的内容选择

5组文字，将其分别放回文章原有位置，以恢复文章原貌。请将答案涂在答题卡相应的位

置上。

why would they falsely confess?

    why on earth would an innocent person falsely confess to committing a crime? to most

people，it just doesn’t seem logical．but it is logical，say expels，if you understand what call happen in a police interrogation(审讯)room．

under t11e right conditions，people’s minds are susceptible(易受影响的)to influence，and the pressure put on suspects during police grillings (盘问)is enormous．       (46)“the

pressure is important to understand．because otherwise it’s impossible to understand why

someone would say he did something he didn’t do．the answer is：to put an end to an

uncomfortable situation that will continue until he does confess．’’

developmental psychologist allison redlich recently conducted a laboratory

determine how likely people are to confess to things they didn’t do．

study to        (47)the researchers then intentionally crashed the computers and accused the participants of hitting the ‘‘alt’’ key to see if they would sign a statement falsely taking responsibility.

   redlich’s findings clearly demonstrate how easy it can be to get people to falsely confess：59 percent of the young adults in the experiment immediately confessed       (48)of

the 1 5-to 1 6-year-olds，72 percent signed confessions，as did 78 percent of the 1 2-to

13-year-olds．

  “there’s no question that young people are more at risk，”says saul kassin，professor at williams college，who has done similar studies with similar results.        (49)

a psychology

  both kassin and redli

         

ch note that the entire ‘‘interrogation” in their experiments consisted of a simple accusation--not hours of aggressive questioning--and still，most participants falsely confessed．

    because of the stress of a police interrogation，they conclude，suspects can become

convinced that falsely confessing is the easiest way out of a bad situation．        (50)

 

a in her experiment．participants were seated at computers and told not to hit the “alt'’ key，because doing so would crash the systems．

b “in some ways，”says kassin，“false confession becomes a rational decision．’’

c  ‘‘it’s a little like somebody’s working on them with a dental(牙齿的)drill，”says franklin zimring，a law professor at the university of california at berkeley.

d “but adults are highly vulnerable too．’’

e how could an innocent person admit to doing something he didn’t do?

f redlich also found that the younger the participant，the more likely a false confession.

 

第6部分：完形填空  (第5~65题，每题1分，共15分)

    阅读下面的短文，文中有15处空白，每处空白给出了4个选项，请根据短文的内容从4个选项中选择1个最佳答案，涂在答题卡相应的位置上。

less is more

     it sounds all wrong--drilling holes in a piece of wood to make it more resistant to knocks．but it works because the energy from the blow gets distributed throughout the wood rather than focusing on one weak spot．the discovery should lead to more effective and lighter packaging materials.

carpenters have known       (51)centuries that some woods are tougher than others．

hickory(山核桃木)，for example，was turned into axe handles and cartwheel spokes(轮辐)

because it can absorb shocks without breaking．white oak，for example，is much more easily

damaged，        (52)it is almost as dense．julian vincent at bathe university and his team

were convinced the wood’s internal structure could explain the differences．

many trees have tubular(管的)vessels that run       (53)the trunk and carry water to the leaves．in oak they are large，and arranged in narrow bands，but in hickory they are smaller，and more evenly distributed．the researchers       (54)this layout might distribute a blow’

         

s energy throughout the wood．soaking up a bigger hit．to test the idea，they drilled holes 0.65 millimetres across into a block of spruce(云杉)，a wood with       (55)vessels，and found

 

 

that      (56)withstood a harder knock．       (57)when there were more than about 30

holes per square centimetre did the wood’s performance drop off．

    a uniform substance doesn’t cope well with knocks because only a small proportion of the material is actually      (58)．all the energy from the blow goes towards breaking the

material in one or two places，but often the pieces left      (59)are pristine(未经破坏的)．

    but instead of the energy being concentrated in one place，the holes provide many weak

spots that all absorb energy as they break，says vincent．“you are controlling the places

       (60)the wood breaks，and it can then absorb more      (61)，more safely．”

the researchers believe the principle could be applied to any material-       (62)

example．to manufacture lighter and more protective packaging．it could        (63)be used

in car bumpers，crash barriers and armour for military vehicles，says ulrike wegst，       (64)the max plank institute for mental research in stuttgart．but she emphasizes that you

       (65)to design the substance with the direction of force in mind．“the direction of

loading is crucial，”she says．

 

51   a  in          b   since           c   for          d   at

52   a  or          b   although        c   and          d   despite

53   a  down          b   over           c   up         

         

d   into

54   a  knew          b   concluded      c   saw         d   thought

55   a  no            b   per            c   each        d   every

56   a  it            b   the idea       c   they        d   spruce

57   a  if            b   just           c   only        d   rarely

58   a  effected      b   beaten         c   slapped     d   affected

59   a  behind        b   beyond         c   for         d   in

60   a  which         b   there          c   that        d   where

61   a  water         b   air            c   energy      d   safety

62   a  among         b   in             c   as          d   for

63   a  also          b   besides        c   else        d   yet

64   a  over          b   at             c   around      d   on

65   a  have          b   must           c   should      d   had

 

满分100分，其中：

l—15每题1分

16—30每题1分

         

31—45每题3分

46—50每题2分

51—65每题1分。

 

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