76. The beaver chews down trees to get food and material with which to build its home.
　　76.水獺啃倒樹木，以便取食物并獲得造窩的材料。
　　77. Poodles were once used as retrievers in duck hunting, but the American Kennel Club does not consider them sporting dogs because they are now primarily kept as pets.
　　77.長卷毛狗曾被用作獵鴨時叼回獵物的獵犬，但是美國Kennel Club卻不承認它們為獵犬，因為它們現在大多數作為寵物飼養。
　　78. As a result of what is now know in physics and chemistry, scientists have been able to make important discoveries in biology and medicine.
　　78.物理學和化學的一個成果是使得科學家們能在生物學和醫學上獲得重大發現。
　　79. The practice of making excellent films based on rather obscure novels has been going on so long in the United States as to constitute a tradition.
　　79.根據默默無聞的小說制作優秀影片在美國由來已久，已經成為傳統。
　　80. Since the consumer considers the best fruit to be that which is the most attractive, the grower must provide products that satisfy the discerning eye.
　　80.因為顧客認為最好的水果應該看起來也是最漂亮的，所以種植者必須提供能滿足挑剔眼光的產品。
　　81. Television the most pervasive and persuasive of modern technologies, marked by rapid change and growth, is moving into a new era, an era of extraordinary sophistication and versatility, which promises to reshape our lives and our world.
　　81.電視，這項從迅速變化和成長為標志的最普及和最有影響力的現代技術，正在步入一個新時代，一個極為成熟和多樣化的時代，這將重塑我們的生活和世界。
　　82. Television is more than just an electronics; it is a means of expression, as well as a vehicle for communication, and as such becomes a powerful tool for reaching other human beings.
　　82.電視不僅僅是一件電器；它是表達的手段和交流的載體并因此成為聯系他人的有力工具。
　　83. Even more shocking is the fact that the number and rate of imprisonment have more than doubled over the past twenty years, and recidivism---that is the rate for re-arrest---is more than 60 percent.
　　83.更讓人吃驚的事實是監禁的數目和比例在過去的二十年中翻了一番還有余，以及累犯率-即再次拘押的比例-為百分之六十強。
　　84. His teaching began at the Massachusetts Institute of Technology, but William Rainey Harper lured him to the new university of Chicago, where he remained officially for exactly a generation and where his students in advanced composition found him terrifyingly frigid in the classroom but sympathetic and understanding in their personal conferences.
　　84.他的教書生涯始于麻省理工學院，但是William Rainey Harper把他吸引到了新成立的芝加哥大學。他在那里正式任職長達整整一代人的時間。他的高級作文課上的學生覺得他在課上古板得可怕，但私下交流卻富有同情和理解。
　　85. The sloth pays such little attention to its personal hygiene that green algae grow on its coarse hair and communities of a parasitic moth live in the depths of its coat producing caterpillars which graze on its mouldy hair. Its muscles are such that it is quits incapable of moving at a speed of over a kilometer an hour even over the shortest distances and the swiftest movement it can make is a sweep of its hooked arm.
　　85.樹獺即不講究衛生，以至于它粗糙的毛發上生出綠苔，成群的寄生蛾生長在它的皮毛深處，變成毛毛蟲，并以它的臟毛為食。她的肌肉不能讓他哪怕在很短的距離以內以每小時一公里的速度移動。它能做的最敏捷的動作就是揮一揮它彎曲的胳膊。
　　86. Artificial flowers are used for scientific as well as for decorative purposes. They are made from a variety of materials, such as way and glass, so skillfully that they can scarcely be distinguished from natural flowers.
　　86.人造花卉即可用于科學目的，也可用于裝飾目的，它們可以用各種各樣的材料制成，臂如蠟和玻璃；其制作如此精巧，幾乎可以以假亂真。
　　87. Three years of research at an abandoned coal mine in Argonne, Illinois, have resulted in findings that scientists believe can help reclaim thousands of mine disposal sites that scar the coal-rich regions of the United States.
　　87.在伊利諾州Angonne市的一個廢棄煤礦的三年研究取得了成果，科學家們相信這些成果可以幫助改造把美國產煤區弄得傷痕累累的數千個舊煤場。
　　88. When the persuading and the planning for the western railroads had finally been completed, the really challenging task remained: the dangerous, sweaty, backbreaking, brawling business of actually building the lines.
　　88.當有關西部鐵路的說服和規劃工作終于完成后，真正艱難的任務還沒有開始；即危險，吃力，需要傷筋動骨和吵吵嚷嚷的建造這些鐵路的實際工作。
　　89. Because of the space crunch, the Art Museum has become increasingly cautious in considering acquisitions and donations of art, in some cases passing up opportunities to strengthen is collections.
　　89.由于空間不足，藝術博物館在考慮購買和接受捐贈的藝術品是越來越慎重，有些情況下放棄其進一步改善收藏的機會。
　　90. The United States Constitution requires that President be a natural-born citizen, thirty-five years of age or older, who has lived in the United States for a minimum of fourteen years.
　　90.美國憲法要求總統是生于美國本土的公民，三十五歲以上，并且在美國居住了至少十四年。