【正文】 sand years, as with mammoth trees. 　　E If a life span is a genetically determined biological characteristic, it is logically necessary to propose the existence of an internal clock, which in some way measures and controls the ageing process and which finally determines death as the last step in a fixed programme. Like the life span, the metabolic rate has for different organisms a fixed mathematical relationship to the body mass. In parison to the life span this relationship is 39。inverted39。: the larger the organism the lower its metabolic rate. Again this relationship is valid not only for birds, but also, similarly on average within the systematic unit, for all other organisms (plants, animals, unicellular organisms). 　　F Animals which behave 39。frugally39。 with energy bee particularly old, for example, crocodiles and tortoises. Parrots and birds of prey are often held chained up. Thus they are not able to 39。experience life39。 and so they attain a high life span in captivity. Animals which save energy by hibernation or lethargy (e. g. bats or hedgehogs) live much longer than those which are always active. The metabolic rate of mice can be reduced by a very low consumption of food (hunger diet). They then may live twice as long as their well fed rades. Women bee distinctly (about 10 per cent) older than men. If you examine the metabolic rates of the two sexes you establish that the higher male metabolic rate roughly accounts for the lower male life span. That means that they live life 39。energetically39。 more intensively, but not for as long. 　　G It follows from the above that sparing use of energy reserves should tend to extend life. Extreme high performance sports may lead to optimal cardiovascular performance, but they quite certainly do not prolong life. Relaxation lowers metabolic rate, as does adequate sleep and in general an equable and balanced personality. Each of us can develop his or her own 39。energy saving programme39。 with a little selfobservation, critical selfcontrol and, above all, logical consistency. Experience will show that to live in this way not only increases the life span but is also very healthy. This final aspect should not be forgotten. 　　Questions 3336　　Complete the notes below. 　　Choose NO MORE THAN TWO WORDS from the passage for each answer. 　　Write your answers in boxes 3336 on your answer sheet. 　　? Objects age in accordance with principles of 33……………… and of 34………………　　? Through mutations, organisms can 35 ……………… better to the environment 　　? 36 ……………… would pose a serious problem for the theory of evolution 　　Questions 3740　　Do the following statements agree with the views of the writer in Reading Passage 3? In boxes 3740 on your answer sheet, write 　　YES if the statement agrees with the views of the writer 　　NO if the statement contradicts the views of the writer 　　NOT GIVEN if it is impossible to say what the writer thinks about this 　　37 The wear and tear theory applies to both artificial objects and biological systems. 　　38 In principle, it is possible for a biological system to bee older without ageing. 　　39 Within seven years, about 90 per cent of a human body is replaced as new. 　　40 Conserving energy may help to extend a human39。s life.READING PASSAGE 3　　篇章結(jié)構(gòu) 體裁 說明文 主題 生物鐘如何工作? 結(jié)構(gòu) A段：萬物都有損耗　　B段：物品變舊與生物衰老的本質(zhì)區(qū)別　　C段：死亡的原理　　D段：人類的平均壽命大致恒定　　E段：生物鐘控制壽命　　F段：能量消耗是關(guān)鍵　　G段：節(jié)約能耗可以延年益壽　　解題地圖　　難度系數(shù)：★★★★　　解題順序：LIST OF HEADINGS→NOTE COMPLETION→YES/NO/NOT GIVEN 　　友情提示：本文的YES/NO/NOTGIVEN可以利用題干中出現(xiàn)的以下表達來猜測答案，一定要記住這些表達一般是選YES或TRUE的標志：　　possible/probable/likely 　　seem to/appear to 　　may/could / can 　　not all/not always/not necessarily 　　必背詞匯　　1. life span壽命　　Captivity vastly reduces the life span of whales. 圈養(yǎng)大大縮短了鯨魚的壽命?！　he life span of human being has been considerably prolonged thanks to the advances i