45. Quails typically have short rounded wings that enable them to spring into full flight instantly when disturbed in their hiding places.
45.典型的鹌鹑都长有短而圆的翅膀，凭此他们可以在受惊时一跃而起，飞离它们的躲藏地。
46. According to anthropologists, the earliest ancestors of humans that stood upright resembled chimpanzees facially, with sloping foreheads and protruding brows.
46.根据人类学家的说法，直立行走的人的鼻祖面部轮廓与黑猩猩相似，额头后倾，眉毛突出。
47. Not until 1866 was the fully successful transatlantic cable finally laid.
47.直到1866年第一条横跨大西洋的电缆才完全成功的架通。
48. In his writing, John Crowe Ransom describes what he considers the spiritual barrenness of society brought about by science and technology.
48. John Crowe Ransom在他的著作中描述了他认为是由科学技术给社会带来的精神贫困。
49. Children with parents whose guidance is firm, consistent, and rational are inclined to possess high levels of self-confidence.
49.父母的教导如果坚定，始终如一和理性，孩子就有可能充满自信。
50. The ancient Hopewell people of North America probably cultivated corn and other crops, but hunting and gathering were still of critical importance in their economy.
50.北美远古的Hopewell人很可能种植了玉米和其他农作物，但打猎和采集对他们的经济贸易仍是至关重要的。
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 attitudes whose principal uniting feature is the belief that government is both harmful and unnecessary.
52.无政府主义这个词描述的是一堆理论和态度，它们的主要共同点在于相信政府是有害的，没有必要的。
53. Probably no man had more effect on the daily lives of most people in the Untied States than did Henry Ford a pioneer in automobile production.
53.恐怕没有谁对大多数美国人的日常生活影响能超过汽车生产的先驱亨利.福特。
54. The use of well-chosen nonsense words makes possible the testing of many basic hypotheses in the field of language learning.
54.使用精心挑选的无意义词汇，可以检验语言学科里许多基本的假定。
55. The history of painting is a fascinating chain of events that probably began with the very first pictures ever made.
55.优化历史是由一连串的迷人事件组成，其源头大概可以上溯到最早的图画。
56. Perfectly matched pearls, strung into a necklace, bring a far higher price than the same pearls told individually.
56.相互般配的珍珠，串成一条项链，就能卖到比单独售出好得多的价钱。
57. During the eighteenth century, Little Turtle was chief of the Miami tribe whose territory became what is now Indiana and Ohio.
57.十八世纪时，"小乌龟"是迈阿密部落的酋长，该部落的地盘就是今天的印第安那州和俄亥俄州。
58. Among almost seven hundred species of bamboo, some are fully grown at less than a foot high, while others can grow three feet in twenty-four hours.
58.在竹子的近七百个品种中，有的全长成还不到一英尺，有的却能在二十四小时内长出三英尺。 liuxuepaper.com