【分析解答题】

Directions: Read the following passage and then give short answers to the five questions. Write your answers on the Answer Sheet.

In many businesses, computers have largely replaced paperwork, because they are fast, flexible, and do not make mistakes. As one banker said, “Unlike humans, computers never have a bad day.” And they are honest. Many banks advertise that their transactions（业务往来）are “untouched by human hands” and therefore safe from human temptation. Obviously, computers have no reason to steal money. But they also have no conscience, and the growing number of computer crimes show they can be used to steal.
16.What is the passage mainly about? .
17. Transactions in many banks are claimed to be safe because they __.
18. The bank teller covered up his crime by ____.
19. What must the librarian do thirty days after she received the notice? .
20. According to the last paragraph, what kind of criminal are the police unable to catch? .