Beginning of Essay
About two hundred years before, the word "computer" started to appear in the dictionary. Some people even didn't know what is a computer. However, most of the people today not just knowing what is a computer, but understand how to use a computer. Therefore, compu ....

Middle of Essay
.... The hard disk of the computer could be endangered by the flood of coffee. Besides, human caretaker of computer system can cause as much as harm as any physical hazard. For example, a cashier in a bank can transfer some money from one of his customer's account to his own account. Nonetheless, the most dangerous thief are not those who work with computer every day, but youthful amateurs who experiment at night --- the hackers. The term "hacker "may have originated at M.I.T. as students' jargon for classmates who labored nights in the computer lab. In the beginning, hackers are not so dangerous at all. They just stole computer time from the universi ....