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。 (来源：老牌的英语学习网站 http://www.EnglishCN.com)
48. In his writing, John Crowe Ransom describes what he considers the spiritua
l 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.
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.
51. Using many symbols makes it possible to put a large amount of inFORMation
on a single map.
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 un
53. Probably no man had more effect on the daily lives of most people in the U
ntied States than did Henry Ford a pioneer in automobile production.
54. The use of well-chosen nonsense words makes possible the testing of many b
asic hypotheses in the field of language learning.
55. The history of painting is a fascinating chain of events that probably beg
an with the very first pictures ever made.
56. Perfectly matched pearls, strung into a necklace, bring a far higher price
than the same pearls told individually.
57. During the eighteenth century, Little Turtle was chief of the Miami tribe
whose territory became what is now Indiana and Ohio.
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.
59. Before staring on a sea voyage, prudent navigators learn the sea charts, s
tudy the sailing directions, and memorize lighthouse locations to prepare them
selves for any conditions they might encounter.
60. Of all the economically important plants, palms have been the least studied.
61. Buyers and sellers should be aware of new developments in technology can a
nd does affect marketing activities.
62. The application of electronic controls made possible by the microprocessor
and computer storage have multiplied the uses of the modern typewriter.
63. The human skeleton consists of more than two hundred bones bound together
by tough and relatively inelastic connective tissues called ligaments.
64. The pigmentation of a pearl is influenced by the type of oyster in which i
t develops and by the depth, temperature, and the salt content of the water in
which the oyster lives.
65. Although mockingbirds superbly mimic the songs and calls of many birds, th
ey can nonetheless be quickly identified as mockingbirds by certain aural clues.
66. Not only can walking fish live out of water, but they can also travel shor
t distances over land.
67. Scientists do not know why dinosaurs became extinct, but some theories pos
tulate that changers in geography, climate, and sea levels were responsible.
68. The science of horticulture, in which the primary concerns are maximum yie
ld and superior quality, utilizes inFORMation derived from other sciences.