73. 随着收入的增加，越来越多的人开始对收藏感兴趣了。(show)
74. 他们本来计划在太阳落山前到达目的地，但意外发生了。(occur)
75. 学习一个国家的语言时，要了解该国的文化和风俗习惯。(learn about)
76. 看着嫦娥一号发回的月亮表面的照片，我为祖国感到自豪。(proud)
77. 如今出国旅游对许多中国人来说不再是个梦想。(no longer)
78. 真难以想象他竟然在这么短的时间内完成了这么艰巨的任务。(complete)
79. 10年前没人能料想到如今这么多的中国人买得起汽车。(afford)

73. As income increases, more and more people began to interest the collectors. (show)
74. They had planned downhill in the sun before it reaches its destination, but the accident happened. (occur)
75. Studying a country's language, to understand the country's culture and customs. (learn about)
76. Chang'e-1 back to looking at the photographs of the moon surface, I am proud of the motherland. (proud)
77. Now travel abroad for many Chinese people is no longer a dream. (no longer)
78. He was really difficult to imagine in such a short time to complete such a daunting task. (complete)
79.10 years ago, no one can think of now expected so many Chinese people can afford cars. (afford)