(74)systems　perform.　basic　tasks,　such　as　recognizing　input　from　the　keyboard,　sending　output　to　the　display　screen,　keeping　track　of　files　and(75)on　the　disk,　and　controlling　peripheral　devices　such　as　disk　drives　and　printers.

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Web browser is simply a terminal emulator, designed to display text on a screen. The two essential differences between an ordinary terminal emulator and a Web browser are that the browser knows how to deal with(71), and that it has a mechanism for(72)graphical files. Display text, display graphics, and(73)hyperlinks--there's 99 percent of the(74)value. That's not to say that the manufacturers didn't go all-out to attach a hyperactive efflorescence of useless capabilities onto their browsers. Remember when media channels in the browser were a big deal, instead of the clutter you can't wait to delete from your favorites of bookmarks menu? Remember when client-side Java applets were supposed to become the preferred(75)for application development? Remember frames and all their nasty side effects?

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(66)is a one-way function that takes an arbitrarily long piece of plaintext and from it computes a fixed-length bit string.(67)is a protocol that most USENET machines how use it to allow news articles to propagate from one machine to another over a reliable connection.(68)is an approach preferred by cable TV providers. In this solution the fiber terminates at an optoelectrical converter and the final segment is a shared coaxial cable.(69)is a device used to connect two separate network that use different communication protocol.(70)js a digital