阅读理解。
阅读下列材料，从A、B、C、D四个选项中选出最佳答案。
John Smith was a good math student at a high school. He loved his computer. He came home early every day. Then he worked with it till midnight. But John was not a good English student, not good at all. He got an F in his English class. One day after school, John joined his computer to the computer in his high school office. The school office computer had the grades of all the students: the math grades, the science grades, the grades in arts and music, and grades in English. He found his English grade. An F! John changed his English grade from F to A. John’s parents looked at his report card. They were very happy. “An A in English!” said John’s Dad. “You are a very clever boy, John. ”
John is a hacker（黑客）. Hackers know how to take information from other computers and put new information in. Using a modem, their computers are connected to other computers secretly. School headmasters and teachers are worried about hackers. So are the police, for some people even take money from bank computer account（帐户）and put it into their own ones. And they never have to leave home to do it! They are called hackers.
1. John changed his English grade with the computer in ______.
A. the classroom B. the school office
C. a bank near his house D. his own house
2. When John’s parents saw the report, they were happy because ______.
A. John was good at math
B. John loved computers
C. John could join one computer to another
D. they thought John was not poor in English any longer.
3. Who are worried about hackers in the story?
A. John’s parents
B. School headmasters, teachers and the police.
C. The police.
D. School headmasters and teachers.
4. What should the hackers know well, do you think, after you read this story?
A. Information B. Bank computer accounts
C. Computers D. Grades
5. The last paragraph is about _______.
A. John B. computers
C. hackers D. modem