75. Though once quite large, the population of the bald eagle across North America has drastically declined in the past forty years.

　　76. The beaver chews down trees to get food and material with which to build its home.

　　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.

　　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.

　　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.

　　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.

　　81. Television the most pervasive and persuasive of modern technologies, marked by rapid change and growth, is movingsintosa new era, an era of extraordinary sophistication and versatility, which promises to reshape our lives and our world.

　　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.

　　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 rearrest------is more than 60 percent.

　　84. His teaching began at the Massachusetts Institute of Technology, but William Rainey Harper lured him to the new university of Chicago,swhereshe remained officially for exactly a generation andswhereshis students in advanced composition found him terrifyingly frigid in the classroom but sympathetic and understanding in their personal conferences.

　　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.

　　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.

　　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-richregions of the United States.

　　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.

　　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.