We all know the Internet does not run fast enough. What we often do not know is why. When a Web page is slow downloading, we usually blame the kind of computer we have, the speed of the connection or the time of day. But in fact there are other things that can figure in, and they are often hidden. Did you know that there are only 13 “root name servers” in the world, serving all 150 million people using the Internet? A root server is a computer that holds the routing information for the naming system of the Internet. It allows your computer to connect with the host computer of, for example, all the www. apple. com pages. It’s like an electronic directory. Each request for a Web page generates at least two transactions well before any real content is communicated—one from the customer to find the name server, and one from the server to confirm the information to the customer. All that back-and-forth generates huge data traffic, so there is some of your slowdown. Significantly, only three of the root name servers are outside the United States in London, StockAholm and Tokyo. This means that an awful lot of Net access generated outside the United States has to go to one of the servers there to find its way. That makes it slow for users. Of course, as with many things about the Internet, the Washington area has a particular advantage. As many as four name servers are here. One is in Hemdon at Network Solutions Inc, and one is College Park at the University of Maryland Computer Science Center. The other two are maintained by the Defense Department's Network Information Center in Vienna and the Army Resource Lab in Aberdeen, Md. But the military rotates(轮换)the servers among secret locations for security purposes. The Net is “distance insensitive”. In other words, the fact that sites are close to each other does not necessarily mean that traffic will move between them faster than between far-apart sites. Singapore and Phnom Perth, for example, are about 750 miles apart. A data trip from one to the other and back takes 1,100 milliseconds. But from Singapore to Los Angeles, which is many more times distant, the data trip is just 400 milliseconds. This has a lot to do with capacity (容量)— the fattest “pipes” of access are to the top-level Internet servers, the backbone computers of the Net, the ones that function like trunk lines, providing long-distance interconnections. If you and the computer host of the page you want to reach are both near a big pipe, signals will travel between you very quickly, even if you are very far away from each other. But even if you are close together the signal will travel slowly if you have a small connecting line.55. Which of the following is the correct description about “root name servers”？A. A root name server is a route for all the Internet's naming systems.B. A root name server is a web page connecting with all the computers.C. A root name server is a hosting computer connecting with web pages.D. A root name server will connect your computer with the hosting computer.56. According to the passage, the speed that a signal travels from one site to another is mainly influenced by ______. A. the distance between two placesB. the capacity of the Internet serverC. the sensitivities of two computersD. the distance between two web sites57. This passage mainly talks about ______.A. why it's slow going on the NetB. all the problems on the InternetC. the root name servers in the worldD. how to request a web page on the Net58. From the passage, we can infer that ______.A. people in America can get access to the Net fasterB. nowhere has more advanced root name servers than in HemdonC. most Net access has to find their ways from American name serversD. distance insensitivity is another factor that affects the signal on the Net英语答案