61. Buyers and sellers should be aware of new developments in technology can and does affect marketing¹ 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。

62. The application of electronic controls made possible by the microprocessor² and computer storage have multiplied the uses of the modern typewriter.

62.电脑储存和由于电子微处理机得以实现的电控运用成倍的增加了现代打字机的功能。

63. The human skeleton consists of more than two hundred bones bound together by tough and relatively³ inelastic connective tissues called ligaments.

63.人类骨骼有二百多块骨头组成，住些骨头石油坚韧而相对缺乏弹性的，被称为韧带的结蒂组连在一起。

64. The pigmentation of a pearl is influenced by the type of oyster⁴ in which it develops and by the depth, temperature, and the salt content of the water in which the oyster lives.

64.珍珠的色泽受到作为其母体牡蛎种类及牡蛎生活水域的深度，温度和含盐度的制约。

65. Although mockingbirds superbly mimic⁵ the songs and calls of many birds, they can nonetheless be quickly identified as mockingbirds by certain aural⁶ clues.

65.尽管模仿鸟学很多种鸟的鸣叫声惟妙惟肖，但人类还是能够依其声音上的线索很快识别它们。

66. Not only can walking fish live out of water, but they can also travel short distances over land.

66.鲇鱼不仅可以离开水存活，还可以在岸上短距离移动。

67. Scientists do not know why dinosaurs⁷ became extinct, but some theories postulate⁸ that changers in geography, climate, and sea levels were responsible.

67.科学家不知道恐龙为何绝种了，但是一些理论推断是地理，气候和海平面的变化造成的。

68. The science of horticulture, in which the primary concerns are maximum yield and superior quality, utilizes⁹ inFORMation derived¹⁰ from other sciences.

68.主要目的在于丰富和优质的农艺学利用了其他科学的知识。

69. Snow aids farmers by keeping heart in the lower ground levels, thereby¹¹ saving 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。

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。