从方框中选择适当的单词，并用其适当的形式完成短文，每词只能用一次，每空一词．

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Since computers were invented in the USA in the 1950s，they have（76）　　very important in many areas of work and leisure．There is no doubt that computers are very（77）　　in the technology and business．In space，computers have been used to control the speed and direction of a spaceship．（78）　　the help of computers，doctors can find diseases easily and solve other problems．For example，tiny computer which are inside patients's bodies can keep（79）　　hearts beating normally．In factories，robots are（80）　　by computers that are like human brains．They can do work（81）　　is dangerous to humans．In business，computers are used to place and cancel orders．They are also making the workplace（82）　　and better．

Since the Internet came into being，people's（83）　　at home have been changed，too．More and more people have（84）　　computers that are used to play games and watch movies．Thanks to the Internet，people can do shopping and do business at home．Instead of writing letters on paper，people communicate by（85）　　e﹣mails and chatting online．The whole world is connected．The Internet is making the world smaller，like a village．