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20世纪是人类通信方式发生巨变的100年。当人类跨入1900年的时候,有线电话还仅是欧洲一些先进国家和美国一些主要城市中的稀罕物,美国电话总数仅有135万部;无线电报通信距离仅百余公里。今天,当人类即将进入21世纪的时候,多媒体通信、光纤通信、卫星通信、数字通信、全球个人通信已成为现代通信的重要特征。实现无论何人、何地、何时的方便的通信,即将成为现实。
The 20th century was a century of tremendous change in the way of human communication. When humans stepped into 1900, the wired telephone was only a rarity in some advanced European countries and some major cities in the United States. The total number of U.S. phones was only 1.35 million; the wireless telegraphy reported a distance of only 100 kilometers. Today, as human beings are about to enter the 21st century, multimedia communications, optical fiber communications, satellite communications, digital communications and global personal communications have become important features of modern communications. Achieving convenient communications no matter who, where, or when will be a reality.