66. Two major factors contributed to devastating summer flooding along the Yangtze River and its tributaries . First ， erosion resulting from excessive deforestation in the upper reaches of the river and ， second ，heavy silting which raised the riverbed in the main channel .

　　兩個(gè)主要因素導(dǎo)致了夏季長(zhǎng)江及其支流的特大洪水。第一，過(guò)度砍伐引起的河流上游的侵蝕，第二，嚴(yán)重的泥沙淤積抬高了主干道的河床。

　　67. Greed and a total lack of social consciousness have been cited as major reasons for the dramatic rise corruption .

　　人們認(rèn)為貪婪和社會(huì)意識(shí)的徹底缺乏是造成腐敗急劇增加的主要原因。

　　68. There are several reasons for the marked increase in China's crime rate-the dramatic influx of itinerant workers in urban areas ; declining social values ; and widening disparities between the haves and have-nots .

　　中國(guó)的犯罪率顯著升高有很多原因——城區(qū)大量流動(dòng)工人的涌入;社會(huì)價(jià)值的貶低以及貧富之間日益擴(kuò)大的差距。

　　69. Why are an increasing number of elderly Chinese parents living apart from their children ? One reason is the increasing upward mobility of the younger generation . Another is expanding social opportunities for the elderly . Perhaps the main reason ， however ， centers on dramatic changes in traditional concepts .

　　為什么越來(lái)越多的中國(guó)老人不和他們的孩子住在一起?原因之一是年輕一代的上進(jìn)心增強(qiáng)了。另一個(gè)原因是社會(huì)上老人的機(jī)會(huì)增加了。然而，主要的原因可能是傳統(tǒng)觀念發(fā)生了巨大變化。

　　70. What has sparked the increasing interest in exercise ? For one thing ， people have gained a greater awareness of the need for physical fitness . For another ， the constantly improving standard of living enables Chinese people to patronize the increasing number of recreational venues . The main thing perhaps centers on the healthcare and psychological benefits exercise provides .

　　什么引發(fā)了人們對(duì)鍛煉越來(lái)越濃的興趣?一方面，人們更加清楚地意識(shí)到保持身體健康的必要性。另一方面，不斷提高的生活水平使中國(guó)人能夠支付增加的娛樂(lè)支出。最主要的可能在于鍛煉帶來(lái)的保健和心理上的好處。

　　71. Identifying the reasons for an emerging phenomenon which involves several complicated factors is far from an easy task . For example ， some scientists attribute environmental deterioration to a series of natural factors ， while others place the blame solely on inappropriate human behavior .

　　要找到涉及許多復(fù)雜因素的新現(xiàn)象的原因遠(yuǎn)非一件易事。例如，一些科學(xué)家把環(huán)境的惡化歸結(jié)為一些自然因素，而另一些人把責(zé)任都推在人類(lèi)不適當(dāng)?shù)男袨樯稀?/P>

　　72. One doesn't have to look far to realize the direct correlation between smoking and cancer .

　　人們不用花費(fèi)很大力氣就能發(fā)現(xiàn)抽煙和癌癥之間的直接聯(lián)系。

　　73. The explanation for the phenomenon of the rising teenage suicide rate involves many complicated factors . Some attribute the rise to an overemphasis on early success ， others point to mounting peer pressure ， and still others to confusion over changing social values .

　　對(duì)上升的少年自殺率的解釋涉及很多復(fù)雜的因素。有的人把上升的原因歸結(jié)為過(guò)分強(qiáng)調(diào)少年時(shí)期的成功，有的人指出是因?yàn)椴粩嘣鲩L(zhǎng)的同伴之間的壓力，還有人認(rèn)為是對(duì)不斷變化的社會(huì)價(jià)值的迷茫造成的。

　　74. The reasons for antisocial behavior are both complicated and varied . I suggest the phenomenon results from inappropriate role models and the lack of well-defined norms of behavior . However ， the main reason is quite likely the continuing degeneration of social values .

　　反社會(huì)行為的原因既復(fù)雜又多樣。我認(rèn)為這種現(xiàn)象是不恰當(dāng)?shù)慕巧�典型和缺少行為�?guī)范的很好的定義造成的。然而，主要原因很可能是不斷貶低的社會(huì)價(jià)值。

　　75. The causes of racial hatred are not readily definable . Sociologists ， however ， attribute them to the misguided concept of a superior race and an innate mistrust of people of color . Perhaps the main cause is quite simply ignorance .

　　種族仇恨的起因沒(méi)有現(xiàn)成的答案。然而，社會(huì)學(xué)家把原因歸結(jié)為被誤導(dǎo)的更高貴的種族的觀念以及天生的對(duì)有色人種的不信任。主要原因可能僅僅是因?yàn)闊o(wú)知。

　　76. The scourge of HIV/AIDS currently engulfing the world will quite likely be brought under control within the next few years thanks to the untiring efforts of scientists and researchers worldwide .

　　現(xiàn)在席卷世界的艾滋病的禍害很有可能由于全世界科學(xué)家和研究人員的不懈努力在未來(lái)幾年內(nèi)得到控制。

　　77. The incidence rate of cancer mainly stems from several factors ， including inappropriate diets ， poor healthcare practices and the lack of early detection . Continuing medical advances and rising awareness do ， however ， offer promising hope for the future .

　　癌癥的發(fā)病率主要由以下諸多因素引起，包括不適當(dāng)?shù)娘嬍场⒉缓玫谋＝×?xí)慣以及沒(méi)有及早發(fā)現(xiàn)。然而，醫(yī)學(xué)的不斷進(jìn)步和對(duì)此不斷增強(qiáng)的關(guān)注給未來(lái)帶來(lái)了很大的希望。

　　78. Increased urban pollution levels and the mounting death toll from motor vehicles accidents can mainly be attributed to the glut of automobiles appearing on city roads in recent years . Detrimental factors will quite likely outweigh the benefits of rising automobile usage .

　　城市人口的增長(zhǎng)和車(chē)禍中死亡率的增加主要是由于近年內(nèi)充斥城市道路的汽車(chē)。汽車(chē)使用量的增加帶來(lái)的有害因素很有可能超過(guò)它的好處。

　　79. The rising divorce rate in China can ， at least in part ， be attributed to spousal incompatibility ， disparities in education levels ， changing social attitudes and the increasing upward mobility of the younger generation .

　　中國(guó)上升的離婚率可以，至少部分可以歸結(jié)為婚姻的不和諧，受教育水平的差異，變化的社會(huì)看法以及年輕一代不斷增強(qiáng)的上進(jìn)心。

　　80. State-owned enterprises are not only failing because of inefficient management ， but also because of their inability to awitch operational modes from the former planned economy to the new market economy .

　　國(guó)有企業(yè)失敗不僅由于低效的管理，也因?yàn)樗麄儾荒軐?shí)現(xiàn)從以前的計(jì)劃經(jīng)濟(jì)到新的市場(chǎng)經(jīng)濟(jì)的運(yùn)作模式的轉(zhuǎn)換。

　　81. Although we do not know the long-term consequences of separation or deprivation ， we do know that they can produce acute immediate distress .

　　雖然我們不知道分離和喪失親人的長(zhǎng)期后果，但我們知道它們能立即引起劇烈的悲痛。

　　82. One can raedily trace the disappearance of dinosaurs to a major cataclysmic event .

　　人們很容易把恐龍消失的原因歸結(jié)為重大的災(zāi)難性事件。

　　83. The raesons for poverty are many ， but for the most part center on illiteracy ， the lack of opportunities and in some cases pure laziness .