為了幫助大家備考托福閱讀，提高成績，下面小編給大家?guī)硗懈ｉ喿xTPO24(試題+答案+譯文)第2篇:Breathing During Sleep，希望大家喜歡!

托福閱讀原文

【1】Of all the physiological differences in human sleep compared with wakefulness that have been discovered in the last decade, changes in respiratory control are most dramatic. Not only are there differences in the level of the functioning of respiratory systems, there are even changes in how they function. Movements of the rib cage for breathing are reduced during sleep, making the contractions of the diaphragm more important. Yet because of the physics of lying down, the stomach applies weight against the diaphragm and makes it more difficult for the diaphragm to do its job. However, there are many other changes that affect respiration when asleep.

【2】During wakefulness, breathing is controlled by two interacting systems. The first is an automatic, metabolic system whose control is centered in the brain stem. It subconsciously adjusts breathing rate and depth in order to regulate the levels of carbon dioxide (CO2) and oxygen (O2), and the acid-base ratio in the blood. The second system is the voluntary, behavioral system. Its control center is based in the forebrain, and it regulates breathing for use in speech, singing, sighing, and so on. It is capable of ignoring or overriding the automatic, metabolic system and produces an irregular pattern of breathing.

【3】During NREM (the phase of sleep in which there is no rapid eye movement) breathing becomes deeper and more regular, but there is also a decrease in the breathing rate, resulting in less air being exchanged overall. This occurs because during NREM sleep the automatic, metabolic system has exclusive control over breathing and the body uses less oxygen and produces less carbon dioxide. Also, during sleep the automatic metabolic system is less responsive to carbon dioxide levels and oxygen levels in the blood. Two things result from these changes in breathing control that occur during sleep. First, there may be a brief cessation or reduction of breathing when falling asleep as the sleeper waxes and wanes between sleep and wakefulness and their differing control mechanisms. Second, once sleep is fully obtained, there is an increase of carbon dioxide and a decrease of oxygen in the blood that persists during NREM.

【4】But that is not all that changes. During all phases of sleep, several changes in the air passages have been observed. It takes twice as much effort to breathe during sleep because of greater resistance to airflow in the airways and changes in the efficiency of the muscles used for breathing. Some of the muscles that help keep the upper airway open when breathing tend to become more relaxed during sleep, especially during REM (the phase of sleep in which there is rapid eye movement). Without this muscular action, inhaling is like sucking air out of a balloon—the narrow passages tend to collapse. Also there is a regular cycle of change in resistance between the two sides of the nose. If something blocks the "good" side, such as congestion from allergies or a cold, then resistance increases dramatically. Coupled with these factors is the loss of the complex interactions among the muscles that can change the route of airflow from nose to mouth.

【5】Other respiratory regulating mechanisms apparently cease functioning during sleep. For example, during wakefulness there is an immediate, automatic, adaptive increase in breathing effort when inhaling is made more difficult (such as breathing through a restrictive face mask). This reflexive adjustment is totally absent during NREM sleep. Only after several inadequate breaths under such conditions, resulting in the considerable elevation of carbon dioxide and reduction of oxygen in the blood, is breathing effort adjusted. Finally, the coughing reflex in reaction to irritants in the airway produces not a cough during sleep but a cessation of breathing. If the irritation is severe enough, a sleeping person will arouse, clear the airway, then resume breathing and likely return to sleep.

【6】Additional breathing changes occur during REM sleep that are even more dramatic than the changes that occur during NREM. The amount of air exchanged is even lower in REM than NREM because, although breathing is more rapid in REM,it is also more irregular, with brief episodes of shallow breathing or absence of breathing. In addition, breathing during REM depends much more on the action of the diaphragm and much less on rib cage action.

托福閱讀試題

1.According to paragraph 1, which of the following can be inferred about the diaphragm during sleep?

A.During sleep the diaphragm requires increased movement of the rib cage.

B.The diaphragm helps with breathing as movements of the rib cage decrease during sleep.

C.The diaphragm requires a great amount of pressure to function properly.

D.The diaphragm contributes to the effective functioning of the rib cage.

2.According to paragraph 2, all of the following are true of the voluntary breathing system EXCEPT:

A.It has its control center in the brain stem.

B.It controls breathing for a number of activities during wakefulness.

C.It is able to bypass the automatic system.

D.It produces an irregular breathing pattern.

3.The word exclusive in the passage (paragraph 3) is closest in meaning to

A.consistent

B.perfect

C.partial

D.sole

4.According to paragraph 3, which of the following may occur just before NREM sleep begins?

A.The automatic, metabolic system may increase its dependence on air exchanges.

B.Breathing can stop for a short time as a person falls asleep.

C.An increase in the oxygen level in the blood can occur as sleep becomes fully obtained.

D.The level of carbon dioxide in the blood may drop suddenly.

5.What is the author's purpose in stating that inhaling is like sucking air out of a balloon?(in paragraph 4)

A.To refute the argument that additional effort is necessary for breathing during sleep.

B.To argue that REM sleep is more important than NREM sleep.

C.To illustrate the difficulty of breathing during sleep.

D.To illustrate how blockage of narrow passages can be prevented during sleep.

6.All of the following are mentioned in paragraph 4 as being characteristic of breathing during sleep EXCEPT

A.relaxation of the muscles involved in the respiratory system.

B.changes in resistance between the two sides of the nose.

C.easier airflow in the passages of the upper airway.

D.absence of certain complex muscle interactions.

7.According to paragraph 5, what happens during NREM sleep when inhaling is difficult?

A.There is an immediate, automatic, adaptive increase in breathing effort.

B.The sleeping person takes several inadequate breaths before the breathing effort is adjusted.

C.The coughing reflex causes the breathing effort to adjust.

D.The airways become cleared as the blood removes irritants.

8.It can be inferred from paragraph 5 that a very mild irritation during sleep will likely cause the sleeping person to

A.increase the breathing effort.

B.wake up and remove the source of irritation.

C.cough while still sleeping.

D.stop breathing temporarily while still sleeping.

9.The word considerable (paragraph 5)meaning to

A.significant.

B.Steady.

C.Usual.

D.necessary.

10.The word resume in the passage (paragraph 5) is closest in meaning to

A.reduce.

B.stop.

C.readjust.

D.restart.

11.Which of the sentences below best expresses the essential information in the highlighted sentence in the passage (paragraph 6)? Incorrect choices change the meaning in important ways or leave out essential information.

A.Because breathing is more shallow and irregular in REM than in NREM, less air is exchanged in REM.

B.Breathing in NREM is less effective than breathing in REM because of irregular episodes of rapid breathing during NREM.

C.Because breathing is more rapid in NREM sleep than in REM sleep, breathing often becomes shallow.

D.Although REM has brief episodes of shallow breathing or lack of breathing, breathing is more rapid than in NREM.

12. Look at the four squares [■] that indicate where the following sentence could be added to the passage. Where would the sentence best fit? Click on a square to add the sentence to the passage. To better understand breathing during sleep, it is, however, helpful to first understand how respiration works in general.

paragraph1: Of all the physiological differences in human sleep compared with wakefulness that have been discovered in the last decade, changes in respiratory control are most dramatic. Not only are there differences in the level of the functioning of respiratory systems, there are even changes in how they function. Movements of the rib cage for breathing are reduced during sleep, making the contractions of the diaphragm more important. [■]【A】 Yet because of the physics of lying down, the stomach applies weight against the diaphragm and makes it more difficult for the diaphragm to do its job. [■]【B】 However, there are many other changes that affect respiration when asleep.

paragraph2: [■]【C】 During wakefulness, breathing is controlled by two interacting systems. [■]【D】The first is an automatic, metabolic system whose control is centered in the brain stem. It subconsciously adjusts breathing rate and depth in order to regulate the levels of carbon dioxide (CO2) and oxygen (O2), and the acid-base ratio in the blood. The second system is the voluntary, behavioral system. Its control center is based in the forebrain, and it regulates breathing for use in speech, singing, sighing, and so on. It is capable of ignoring or overriding the automatic, metabolic system and produces an irregular pattern of breathing.

13.Directions: From the seven statements below, select the statements that correctly characterize breathing during wakefulness and those statements that correctly characterize breathing during sleep. Drag each answer choice you select into the appropriate box of the table. Two of the answer choices will NOT be used. This question is worth 3 points.

A.The role of the rib cage increases and the role of the diaphragm decreases.

B.Carbon dioxide in blood rises and oxygen drops.

C.The coughing reflex is extremely complex.

D.A great deal of effort is used for breathing.

E.Upper airways are resistant to colds and allergies.

F.There is a drop in the volume of air that is exchanged.

G.Automatic and voluntary respiratory systems are both involved.

1 )

Wakefulne

A B C D E F G

2 )

Sleep

A B C D E F G

托福閱讀答案

1.以diaphragm做關鍵詞定位至第三句和第四句，說ribcage運動變少，使得diaphragm更重要，但stomach的壓力使得diaphragm工作起來更困難，B是正確答案。A的increased movement of the rib cage和C的需要pressure都與原文相反;D說diaphragm contributes to原文沒有說。

2.EXCEPT題，排除法。A的centered in brain stem做關鍵詞定位至第一句，但原文說這個特點是屬于automatic，metabolic system的，而voluntary的center是在forebrain，所以A錯，選;B的a number of activities做關鍵詞定位至倒數(shù)第二句的一大堆活動，所以B正確，不選;C的bypass the automatic system和D的irregular breathing pattern做關鍵詞都定位至最后一句，都正確，不選。

3.exclusive僅有，只有，排他，所以正確答案是sole。從單詞本身看，include→exclude→exclusive，所以一定能得出排他之意。原句說在NREM期間，automatic系統(tǒng)怎么控制breathing，使得氧的需求量減少，前面一直在說兩個系統(tǒng)，現(xiàn)在氧的需求量減少了，肯定是有系統(tǒng)不干活了，所以就是只有automatic在干活，所以答案是D只有。A持續(xù)、B完美，都不靠譜，C的partial剛好與原文意思相反，也不選。

4.此題關鍵詞難找，可以順序向下看，也可以用排除法，如果順序向下看的話，會看到第一點說的是當sleeper在睡與醒之間搖擺的時候，發(fā)生了呼吸cessation，也就是stop，所以正確答案是B，stop for a short time。C和D一個說氧上升一個說二氧化碳下降，是一回事，都不是在睡覺期間發(fā)生的，所以都反了，而且兩個一樣的也都不選，A沒說。

5.修辭目的題，先看修辭點所在的句子，但原句整個都是一個例子，往前看。前一句仍然在說肌肉relax的事情，因此也是例子，所以看開頭，開頭說air passage在睡覺期間變了很多緊接著就解釋睡覺期間呼吸很難，也就是開頭所指的變化是睡覺的時候呼吸變難，所以正確答案是C。A的refute與原文相反;B的比較和D的prevent blockage原文都沒說。

6.EXCEPT題，排除法。A的relaxation of the muscles做關鍵詞定位至第三句，正確，不選;B的two sides of the nose做關鍵詞定位至倒數(shù)第三句，正確，不選;C的upper airway做關鍵詞定位至第三句，但答案的easier airflow原文完全沒說，C錯，選;D的complex muscle interaction做關鍵詞都定位至最后一句，正確，不選。

7.以inhaling is difficult做關鍵詞定位至第二句，但這句只說了difficult的事兒，沒說發(fā)生了什么，往下看。下句說NREM期間什么adjustment都沒有，只有在inadequate breaths之后才adjust，所以答案是B。A是wakeful時候才有的;C的因果關系原文沒說;D完全沒說。

8.以irritation做關鍵詞定位至最后一句，說如果irritation太嚴重，睡著的人就會醒，按照正常的敘述順序應該是先敘述mild的情況，前一句果然在說coughing reflex沒產(chǎn)生cough，而產(chǎn)生了cessation of breathing，呼吸停止的狀況，所以答案是D。C與原文相反;B是severe的時候才有的，A沒說。

9.considerable可觀的，相當?shù)?，重要的，所以正確答案是significant。從單詞本身看，consider的考慮的意思是很常見的，加形容詞詞尾able變?yōu)橹档每紤]的，所以也是significant。原文說在若干次inadequate breaths之后，二氧化碳含量怎么上升氧氣含量下降，才能調(diào)整breathing，一般我們說顯著的變化，所以答案A，其他答案都不靠譜。

10.resume重新開始，再繼續(xù)，所以正確答案是restart。原句說如果irritation太嚴重了，睡著的人會醒來，清理呼吸道，并且怎么呼吸，前一句都說了因為irritants呼吸停止，然后醒來，當然清理完就繼續(xù)呼吸了唄，答案是D。A和B完全不靠譜，如果選C，之前應該adjust一次，但之前從來沒說irritation嚴重的時候有先調(diào)整一次，所以C錯。

11.原句的結構是exchange lower是因為blabla，所以正確答案是A，因果關系和結構都正確。其他答案都沒提到exchange lower這個主干，而且B把原文非主干的部分變成了主干;C結果搞亂;D邏輯關系錯。

12.兩個過渡點，名詞respiration和連詞however。根據(jù)respiration可以初步確定答案是B或者C，但根據(jù)however斷定B不對，因為兩個however不能連續(xù)出現(xiàn)，所以正確答案是C。

13.第一段和第二段在講wakeful部分，其余在講sleep部分。The role選項對應第一段第三句，屬于wakeful部分。Carbon dioxide選項對應第五段第四句，二氧化碳多氧少，屬于sleep部分。The coughing選項原文沒說reflex復雜，不屬于任何一列，不選。A great deal選項對應原文第四段第三句，屬于sleep部分。Upper airways選項原文沒說，不選。There is選項對應原文第六段第二句，屬于sleep部分。Automatic選項對應原文第二段首句，屬于wakeful部分。

托福閱讀譯文

【1】關于人類睡覺和清醒時生理狀態(tài)的差異在過去的十年里已被發(fā)現(xiàn)，在所有的這些差異中，呼吸系統(tǒng)控制方面的變化尤其引人注目。不僅是呼吸系統(tǒng)運作水平有差異，在如何運作方面也出現(xiàn)了變化。胸腔所做的呼吸運動在睡覺時會減少，使得橫膈膜的收縮變得更為重要。然而由于躺下來的物理作用，胃部壓迫橫膈膜使得橫膈膜難以工作。不管怎樣，睡眠時還有很多其他的變化影響著呼吸。

【2】清醒的時候，呼吸受到兩個互相影響的系統(tǒng)的控制。第一個是自動的新陳代謝系統(tǒng)，它的控制中心在腦干。它會潛意識的調(diào)整呼吸頻率和深度來控制二氧化碳和氧氣的濃度以及血液中的酸堿比。第二套系統(tǒng)是自發(fā)行為系統(tǒng)。它的控制中心在前腦，調(diào)節(jié)說話、唱歌、嘆息等行為時的呼吸。它能忽略或無視自動新陳代謝系統(tǒng)并且產(chǎn)生無規(guī)律的呼吸模式。

【3】在NMER(睡覺時沒有快速眼部活動的階段)這個階段中，呼吸會變得更深更有規(guī)律，但是呼吸頻率會降低，導致總體空氣交換減少。發(fā)生這個是因為在NREM睡眠階段中，自動的新陳代謝系統(tǒng)會獨自控制呼吸，身體會利用更少的氧氣產(chǎn)生更少的二氧化碳。同時，自動的新陳代謝系統(tǒng)對血液中二氧化碳和氧氣的含量反應并不靈敏。在睡眠中呼吸控制的變化會導致兩個結果。第一，睡著時呼吸可能會有短暫的停止或減少，因為睡眠者在睡眠和清醒之間徘徊，而這兩種狀態(tài)的控制系統(tǒng)不一樣。第二，一旦得到了充足的睡眠，血液中二氧化碳含量升高而氧氣含量降低，在NREM階段也會持續(xù)這樣。

【4】但這并不是全部的變化。在睡眠的所有階段中，氣道的一些變化已經(jīng)被觀察到了。睡眠時需要付出兩倍的努力去呼吸，因為呼吸道氣流的阻力會比較強并且用來呼吸的肌肉的效率會有變化。一些在呼吸時幫助保持上呼吸道通暢的肌肉在睡覺的時候會變得松弛，特別是在REM階段(就是有快速眼部運動的睡眠階段)。沒有這種肌肉運動，呼吸空氣就像從氣球里吸氣一樣，狹窄的通道會面臨崩潰。而且鼻子兩側的阻力也會周期性改變。如果有時候堵塞了“好”的一邊，比如過敏和感冒引起的堵塞，阻力就會大大增加。與這些因素一起的是那些能夠改變從鼻子到嘴巴的氣流路徑的肌肉之間失去了復雜的交互。

【5】其他呼吸調(diào)節(jié)機制在睡眠時顯然要停止運作。比如說，在清醒時如果呼吸變得困難的話就會有一個立即自動適應性的呼吸增強(比如戴上面具呼吸)。但在NREM狀態(tài)時完全不存在這樣反射性的調(diào)節(jié)。在這種情況下，只有幾次不充分的呼吸后使得血液中二氧化碳的含量顯著提升以及氧氣的含量降低，呼吸才會被調(diào)整過來。最后，咳嗽反應在應對呼吸道中刺激物時產(chǎn)生的不是睡覺時咳嗽而是呼吸停止。如果刺激物足夠嚴重，睡著的人會醒來清理氣道，然后繼續(xù)呼吸很可能再度入睡。

【6】發(fā)生在REM時期的多余的呼吸變化比發(fā)生在NREM時期的呼吸變化更顯著。REM的空氣交換量要比NREM低，因為盡管REM中呼吸更加急促，但也更加沒有規(guī)律，包括一些簡短的淺呼吸或呼吸暫停。另外，REM時期的呼吸更多取決于橫膈膜而不是胸腔的作用。

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