Meta search engines do not have a database with URLs and descriptions. Instead they have a database of search engines. If you enter your keywords into a meta search engine it will send out requests to all the directories and crawlers it has stored in its database. The meta search engines with a more sophisticated application in the background are able to detect double URLs which come back from the various search engines and present only a single URL to the customer.
34. Crawler is a kind of__________.
A. worm B. search engine
C. service D. directory
35. The disadvantage of Crawler is that it__________.
A. provides a complete database
B. takes too much time to find the needed information
C. provides too much useless information
D. gives response to every quest
36. Who can input information to the web directories?
A. Only webmasters.
B. Both directory maintainers and webmasters.
C. Any one who wants to announce a web page.
D. Any one who has found a new web page.
Passage 3
In what seems like the prehistoric times of computer history; the earth’s postwar era, there was quite a widespread rumor that computers would take over the world from man one day. Already today, less than fifty years later, as computers are relieving us of more and more of the routine tasks in business and in our personal lives, we are faced with a less dramatic but not less foreseen problem. People tend to be over-trusting of computers and are reluctant to challenge their authority. Indeed, they behave as if they were hardly aware that wrong buttons may be pushed, or that a computer may simply malfunction.
Obviously, there would be no point in investing in a computer if you had to check all its answers, but people should also rely on their own internal computers and check the machine when they have the feeling that something has gone wrong. |
