2．Rene Descartes'explanation of pain has long been acknowledged in medicine．He proposed that pain is a purely physical phenomenon-that tissue injury makes specific nerves send a signal to the brain，causing the mind to notice pain．The phenomenon，he said，is like pulling on a rope to ring a bell in the brain．It is hard to overstate how deeply fixed this account has become．In medicine，doctors see pain in Descartes'terms-as a physical process，a sing of tissue injury．
The limitations of this explanation，however，have been apparent for some time，since people with obvious injuries sometimes report feeling no pain at all．Later，researchers proposed that Descartes'model be replaced with what they called the gate control theory of pain．They argued that before pain signals reach the brain，they must first go through a gating mechanism in the spinal cord（脊髓）．In some cases，this imaginary gate could simply step gain signals from getting to the brain．
Their most amazing suggestion was that what controlled the gate was not just signals from sensory nerves but also emotions and other"output"from the brain．They were saying that pulling on the rope need not make the bell ring．The bell itself-the mind-could stop it．This theory led to a great deal of research into how such factors as mood，gender，and beliefs influence the experience of pain．In a British study，for example，researchers measured pain threshold and tolerance levels in 53 ballet dancers and 53 university students by using a common measurement：after immersing your hand in body-temperature water for two mintues to establish a baseline condition，you put your hand in a bowl of ice water and start a clock running．You mark the time when it begins to hurt：that is your pain threshold．Then you mark the time when it hurts too much to keep your hand in the water：that is your pain tolerance．The test is always stopped at 120 seconds，to prevent injury．
The results were striking．On average female students reported pain at 16 seconds and pulled their hands out of the ice water at 37 seconds．Female dancers were almost three times as long on both counts．Men in both groups had a higher threshold and tolerance for pain，but the difference between mals dancers and mals nondancers was nearly as large．What explains that difference？Probably it has something to do with the psychology of ballet dancers-a group known for self-discipline，physical fitness，and competitiveness，as well as by a high rate of chronic（慢性）injury．Their driven personalities and competitive culture evidently accustom them to pain．Other studies along these lines have shown that outgoing people have greater pain tolerance and that，with training，one can reduce one's sensitivity to pain．
There is also striking evidence that very simple kinds of mental suggestion can have powerful effects on pain．In one study of 500 patients undergoing dental procedures，those who were given a placebo injection and promised that it would relieve their pain had the least discomfort-not only less than the patients who got a placebo and were told nothing but also less than the patients who got actual drug without any promise that it would work．
Today it is abundantly evident that the brain is actively involved in the experience of pain and is no more bell on a string．Today every medical textbook teaches the gate control theory as fact．There's a problem with it，though．It explains people who have injuries but feel no pain，but it doesn't explain the reverse，which is far more common-the millions of people who experience chronic pain，such as back pain，with no signs of injury whatsoever．So where does the pain come from？The rope and clapper are gone，but the bell is still ringing．
50．The primary purpose of the passage is toA．
A．describe how modern research has updated an old explanation．
B．support a traditional view with new data．
C．promote a particular attitude towards physical experience．
D．suggest a creative treatment for a medical condition．
51．Which statement best describes Descartes theory of pain presented in paragraph 1？D
A．The brain can shut pain off at will．
B．The brain plays no part in the body's experience of pain．
C．Pain can be caused in many different ways．
D．Pain is an automatic response to bodily injury．
52．The author implies that the reason why the gate control was"amazing"was that itA
A．offered an extremely new and original explanation．
B．was just opposite to people's everyday experiences．
C．was grounded in an ridiculous logic．
D．was so sensible it should have been proposed centuries before．
53．The author refers to"chronic back pain"as an example of something that isB
A．costly，because it troubles millions of people．
B．puzzling，because it sometimes has no obvious cause．
C．disappointing，because it does not improve with treatment．
D．worrying，because it lies beyond the reach of medicine．
54．The last sentence of the passage serves mainly to express thatC
A．scientific judgments are difficult to understand．
B．theoretical investigations are generally useless．
C．researchers still have a long way to go before the puzzle is made clear．
D．there is always something puzzling at the heart of science．
分析 本文介绍了人类对于疼痛的研究理论的发展变化，早期Rene Descartes认为疼痛是一种纯粹的生理现象，受伤的器官让特别的神经系统发送信号给大脑，使得大脑注意到疼痛，而后来又知道我们的身体上有控制疼痛的门，而疼痛的信号不仅仅来自神经而且也和情感以及其他大脑产生的东西有关，但是控制门的理论可以解释人们受伤了却没有感到疼痛，但是它不能解释反面的例子，数百万的人有慢性的疼痛，例如后背的疼痛，可是他们却没有受伤的迹象，所以在弄清楚这个困惑之前研究者仍旧有很长的一段路要走．
解答 50．答案：A．主旨大意题．根据每一段的第一句Rene Descartes'explanation of pain has long been acknowledged in medicine（Rene Descartes的介绍在医疗届一直被认可）；The limitations of this explanation，however，have been apparent for some time，since people with obvious injuries sometimes report feeling no pain at all（这种解释的局限性在有时候是非常明显的，因为有时候人们明显是受伤了却根本没有感到疼痛）；Their most amazing suggestion was that what controlled the gate was not just signals from sensory nerves but also emotions and other"output"from the brain（这些研究者最令人吃惊的研究结果控制疼痛的门的信号不仅仅来自神经而且也和情感以及其他大脑产生的东西有关）；The results were striking（这个结果是令人震惊的）；There is also striking evidence that very simple kinds of mental suggestion can have powerful effects on pain（有证据表明非常简单的精神因素就会对疼痛产生有力的影响）；Today it is abundantly evident that the brain is actively involved in the experience of pain（今天又明显的证据表明大脑积极参与了疼痛的体验），所以知道答案是A describe how modern research has updated an old explanation（描述现代研究更新了一个原有的解释．）
51．答案：D．根据每一段的第二句He proposed that pain is a purely physical phenomenon-that tissue injury makes specific nerves send a signal to the brain，causing the mind to notice pain．可以知道他认为疼痛是一种纯粹的生理现象，受伤的器官让特别的神经系统发送信号给大脑，使得大脑注意到疼痛，所以知道答案是D．Pain is an automatic response to bodily injury（疼痛是对身体伤害的自动反应．）
52．答案：A．细节推理题．根据每一段的第二句He proposed that pain is a purely physical phenomenon-that tissue injury makes specific nerves send a signal to the brain，causing the mind to notice pain可以知道原来的理论认为疼痛是一种纯粹的生理现象，受伤的器官让特别的神经系统发送信号给大脑，使得大脑注意到疼痛，而第三段的第一句Their most amazing suggestion was that what controlled the gate was not just signals from sensory nerves but also emotions and other"output"from the brain表明有控制疼痛的门，而疼痛的信号不仅仅来自神经而且也和情感以及其他大脑产生的东西有关，所以选择A．offered an extremely new and original explanation提出了一个极度新的根本的解释．
53．答案：B．细节题．根据末段第二行It explains people who have injuries but feel no pain，but it doesn't explain the reverse，which is far more common-the millions of people who experience chronic pain，such as back pain，with no signs of injury whatsoever．So where does the pain come from可以知道控制门的理论可以解释人民受伤了却没有感到疼痛，但是它不能解释反面的例子，数百万的人有慢性的疼痛，例如后背的疼痛，可是他们却没有受伤的迹象，所以选择B puzzling，because it sometimes has no obvious cause这个现象是令人困惑的，因为有时候没有明显的原因．
54．答案：C．细节题．根据划线句子的前几句可以知道控制门的理论可以解释人民受伤了却没有感到疼痛，但是它不能解释反面的例子，数百万的人有慢性的疼痛，例如后背的疼痛，可是他们却没有受伤的迹象，即绳子和拍手没有了，可铃仍旧在响，所以选择C．researchers still have a long way to go before the puzzle is made clear在弄清楚这个困惑之前研究者仍旧有很长的一段路要走．
点评 考查阅读理解．
这是阅读表达题，这种题的解答方法主要是：
1．根据题干中的定位词寻找信息句
2．根据需要对信息句进行重组，整合
3．根据上下文，结合构词法进行猜测
