91. Arid regions in the southwestern United States have become increasingly inviting playgrounds for the growing number of recreation seekers who own vehicles such as motorcycles or powered trail bikes and indulge in hill-climbing contests...

81. Television the most pervasive and persuasive of modern technologies, marked by rapid change and growth, is 0 81. television the most pervasive and persuasive of modern technologies, marked by rapid change and growth, is moving into a ne...

71. People in prehistoric times created paints by grinding materials such as plants 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 annoyin...

61. buyers and sellers should be aware of new developments in technology can and does affect marketing activities. 61.购买者和销售者都应该留意技术的新发展，原因很简单，因为技术能够并且已经影响着营销活动...

51. using many symbols makes it possible to put a large amount of information on a single map. 51.使用多种多样的符号可以在一张地图里放进大量的信息。 52. anarchism is a term describing a cluster of doctrines and atti...

41. the annual worth of utahs manufacturing is greater than that of its mining and farming combined. 41.尤它州制造业的年产值大于其工业和农业的总和。 42. the wallflower is so called because its weak stems often grow on...

31. although apparently rigid, bones exhibit a degree of elasticity that enables the skeleton to withstand considerable impact. 31.骨头看起来是脆硬的，但它也有一定的弹性，使得骨骼能够承受相当的打击。 32. th...

21. Eliminating problems by transferring the blame to others is often called scape-goating. 21.用怪罪别人的办法来解决问题通常被称为寻找替罪羊。 22. The chief foods eaten in any country depend largely on what grows be...

11. acids are chemical compounds that, in water solution, have a sharp taste, a corrosive action on metals, and the ability to turn certain blue vegetable dyes red. 11.酸是一种化合物，它在溶于水时具有强烈的气味和对金属...

1. Typical of the grassland dwellers of the continent is the American antelope, or pronghorn. 1.美洲羚羊，或称叉角羚，是该大陆典型的草原动物。 2. Of the millions who saw Haleys comet in 1986, how many people will live...