Begun in the late 1960s by Pentagon weapons researchers as a system for easing

communication between computers in disparate electric networks,

the Internet has evolved 【M1】__

into a popular vehicle for scientific research, communication, entertainment, and more. It

links together thousands of computer networks such as

those belonging to corporations, 【M2】__

commercial services, universities, and research centers, joining them as branches on a tree

to larger networks known as backbones. Once a computer is on-line, that is, connected by

modem or networking equipment of the Internet,

the user can search through data banks 【M3】__

for documents, chat with other computer users,

or instant send opinions and observations 【M4】__

to the likes of President Bill Clinton, film critic Roger Ebert, or rocker Billy Idol (just to name

a few). No central governing body runs the Internet,

and nobody has an exact census of 【M5】__

users. But estimates of the number already range from around 10 million to as high as 5

million. Well over 10,000 separated computer networks

are connected by the Internet, and 【M6】__

total traffic was expected to double during 1993. Today, the Internet is free resources and

commercial services that provide databases and computer files with a fee.

Publishers are 【M7】__

seeking to make books and periodicals available on the Internet as a profit-making adventure.

Meanwhile, works in the public domain have begun appearing on the Internet for【M8】__

users to "upload" to their computers virtually free of charge.

With electronic access to data 【M9】__

from all over the world, scholarly research that in the past would have required months of

travel could now be done at one' s desk. 【M10】__

【M1】