It is 3 A. M. Everything on the university campus seems ghostlike in the quiet, misty dark

ness -- everything except the computer center. Here, twenty students untidy and blurred-eyed, sit transfixed at their consoles([计]挖制台), tapping away on the terminal keys. With eyes glued to the video screen, they tap on for hours. For the rest of the world, it might be the middle of the night, but here time does not exist. This is a world unto itself. These young computer "hackers" are pursuing a kind of impulse, a drive so consuming it overshadows nearly every other part of their lives and forms the focal point of their existence. They are compulsive computer programmers. Some of these students have been at the console for thirty hours or more without a break for meals or sleep. Some have fallen asleep on sofas or chairs in the computer center, trying to catch a few winks but hate to get too far away from their beloved machines.

Most of these students don't have to be at the computer center in the middle of the night. They aren't working on assignments. They are there because they want to be -- they are irresistibly drawn there.

And they are not alone. There are hackers at computer centers all across the country. In their extreme form, they focus on nothing else. They flunk(考试不及格)out of school and lose contact with friends; they might have difficulty finding jobs, choosing instead to wander from one computer center to another. They may even decline personal cleanliness.

"I remember one hacker. We literally had to carry him off his chair to feed him and put him to sleep. We really feared for his health," says a computer science professor at MIT.

Computer science teachers are now more aware of the implications of this hacker phenomenon and are

on the lookout for potential hackers and cases of computer addiction that are already severe. They know that the case of the hackers is not just the story of one person's relationship with a machine. It is the story of a society's relationship to the so-called thinking machines, which are becoming almost everywhere.

We can learn from the passage that those at the computer center in the middle of the night are ______.

A．students preparing for tests

B．students using computers to finish assignments

C．excellent computer science majors

D．students deeply fascinated by the computer