69. Snow aids farmers by keeping heart in the lower ground levels, thereby sav
ing the seeds from freezing.
69.雪对农民是一种帮助，因为它保持地层土壤的温度，使种子不致冻死。 (来源：英语学习门户 http://www.EnglishCN.com)

70. Even though the precise qualities of hero in literary words may vary over
time, the basic exemplary function of the hero seems to remain constant.
70.历代文学作品中的英雄本色虽各有千秋，但其昭世功力却是恒古不变的。

71. People in prehistoric times created paints by grinding materials such as p
lants and clay into power and then adding water.
71.史前的人们制造颜料是将植物和泥土等原料磨成粉末，然后加水。

72. Often very annoying weeds, goldenrods crowd out less hardy plants and act
as hosts to many insect pests.
72.黄菊花通常令人生厌，它挤走不那么顽强的植物，并找来很多害虫。

73. Starting around 7000 B.C., and for the next four thousand years, much of t
he Northern Hemisphere experienced temperatures warmer than at present.
73.大约从公元前七千年开始，在四千年当中，北半球的温度比现在高。

74. When Henry Ford first sought financial backing for making cars, the very n
otion of farmers and clerks owning automobiles was considered ridiculous.
74.当亨利.福特最初制造汽车为寻求资金支持时，农民和一般职员也能拥有汽车的想法被
认为是可笑的。

75. Though once quite large, the population of the bald eagle across North Ame
rica has drastically declined in the past forty years.
75.北美秃头鹰的数量一度很多，但在近四十年中全北美的秃头鹰数量急剧下降。

76. The beaver chews down trees to get food and material with which to build i
ts home.
76.水獭啃倒树木，以便取食物并获得造窝的材料。

77. Poodles were once used as retrievers in duck hunting, but the American Ken
nel Club does not consider them sporting dogs because they are now primarily k
ept as pets.
77.长卷毛狗曾被用作猎鸭时叼回猎物的猎犬，但是美国Kennel Club却不承认它们为猎犬，
因为它们现在大多数作为宠物饲养。

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.物理学和化学的一个成果是使得科学家们能在生物学和医学上获得重大发现。

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.根据默默无闻的小说制作优秀影片在美国由来已久，已经成为传统。

80. Since the consumer considers the best fruit to be that which is the most a
ttractive, the grower must provide products that satisfy the discerning eye.
80.因为顾客认为最好的水果应该看起来也是最漂亮的，所以种植者必须提供能满足挑剔眼
光的产品。

81. Television the most pervasive and persuasive of modern technologies, marke
d by rapid change and growth, is moving into a new era, an era of extraordinar
y sophistication and versatility, which promises to reshape our lives and our
world.
81.电视，这项从迅速变化和成长为标志的最普及和最有影响力的现代技术，正在步入一个
新时代，一个极为成熟和多样化的时代，这将重塑我们的生活和世界。

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 fo
r reaching other human beings.
82.电视不仅仅是一件电器；它是表达的手段和交流的载体并因此成为联系他人的有力工具.

83. Even more shocking is the fact that the number and rate of imprisonment ha
ve more than doubled over the past twenty years, and recidivism——that is the
 rate for re-arrest——is more than 60 percent.
83.更让人吃惊的事实是监禁的数目和比例在过去的二十年中翻了一番还有余，以及累犯率
——即再次拘押的比例——为百分之六十强。

84. His teaching began at the Massachusetts Institute of Technology, but Willi
am Rainey Harper lured him to the new university of Chicago, where he remained
 officially for exactly a generation and where his students in advanced compos
ition found him terrifyingly frigid in the classroom but sympathetic and underst
anding in their per
sonal conferences.
84.他的教书生涯始于麻省理工学院，但是William Rainey Harper把他吸引到了新成立的
芝加哥大学。他在那里正式任职长达整整一代人的时间。他的高级作文课上的学生觉得他
在课上古板得可怕，但私下交流却富有同情和理解。

85. The sloth pays such little attention to its personal hygiene that green al
gae grow on its coarse hair and communities of a parasitic moth live in the de
pths of its coat producing caterpillars which graze on its mouldy hair. Its mu
scles are such that it is quits incapable of moving at a speed of over a kilomet
er an hour even ove
r the shortest distances and the swiftest movement it can make is a sweep of i
ts hooked arm.
85.树獭即不讲究卫生，以至于它粗糙的毛发上生出绿苔，成群的寄生蛾生长在它的皮毛深
处，变成毛毛虫，并以它的脏毛为食。她的肌肉不能让他哪怕在很短的距离以内以每小时