There are usually two ways to inquire the telephone number, one is to look through the telephone book, and the other is to dial "1 14" (telephone number inquiry desk). Phone books are not everywhere, and they are not so easy to find. Call "1 14" and it will tell you the answer quickly and accurately as long as you ask, so the "1 14" information desk is becoming more and more popular. At present, Shanghai Enquiry Center handles180,000 calls every day on average, and "1 14" has become one of the indispensable telecommunication services in modern civilized society. The early "1 14" relied on manual query. Before taking up their posts, full-time inquirers often have to memorize hundreds of commonly used telephone numbers and prepare a lot of classified cards around them for easy reference at any time. When you ask for her familiar number, she will tell you immediately, otherwise she will have to flip the card and answer you when she finds it. In this way, you often have to wait for a while when you look up the number. At present, the inquiry service is basically completed by computers. There is much more information stored in the computer than in the phone book. When the inquirer receives your inquiry, she only needs to press a few keys briefly on the computer, and the computer will imitate the human voice through a special "simulator" to quickly find the phone number you want and report it. In order to make the computer complete the inquiry work quickly and correctly, it is usually necessary to establish a "database" in which thousands of telephone numbers in Qian Qian are stored in order according to certain rules, so as to be ready for inquiry at any time. There are many ways to arrange telephone numbers, such as industry, agriculture, commerce, transportation, justice, culture, education and tourism. And industry can be divided into heavy industry and light industry, light industry can be divided into textiles and household appliances, and household appliances can be divided into washing machines, television and many other different occupations. For another example, you can put all the company names in alphabetical order. Of course, there are many ways to establish a database and find it, and the actual situation is much more complicated. However, due to the extremely fast operation speed of the computer, more than hundreds of thousands of times and millions of times per second, even if this query is complicated, it is just a piece of cake for the computer, easy to handle, and can give an answer in an instant, almost without the inquirer waiting.