Most worms work by exploiting weaknesses in an operating system, but whoever wrote Blaster had a particularly refined sense of humour, since the website under attack was the one from which users could obtain a program to fix the very weakness in Windows that the worm itself was exploiting.

　　One way to deal with a wicked worm like Blaster is to design a fairy godmother worm that goes around repairing vulnerable machines automatically. In the case of Blaster someone seems to have tried exactly that with a program called Welchi. However, according to Mr Haley, Welchi has caused almost as many problems as Blaster itself, by overwhelming networks with “pings”—signals that checked for the presence of other computers.

　　Though both of these programs fell short of the apparent objectives of their authors, they still caused damage. For instance, they forced the shutdown of a number of computer networks, including the one used by the New York Times newsroom, and the one organising trains operated by CSX, a freight company on America's east coast.

　　Computer scientists expect that it is only a matter of time before a truly devastating virus is unleashed.

26. SoBig.F damaged computer programs mainly by ____.
[A] sending them an overpowering number of messages
[B] harvesting the addresses stored in the computers
[C] infecting the computers with an invisible virus
[D] destroying the anti-virus software of the computers

27. Which of the following best defines the word “ doctored” (line , para. 1) ?
[A] falsified [B] cured
[C] deceived [D] diagnosed

28. Compared with SoBig.F, Blaster was a virus that was _____.
[A] more destructive
[B] more humorous
[C] less vulnerable
[D] less noticeable

29. From the text we learn that Welchi ____.
[A] is a wicked worm causing as many damages as Blaster did
[B] is a program designed by Haley to detect worms like Blaster
[C] is a program intended to fix the infected machines
[D] is a worm meant to defeat the virus with “ pings”

30. The tone of the text can best described as _____.
[A] optimistic and humorous
[B] analytical but concerned
[C] passionate but pessimistic
[D] scholarly and cautious

Text 3

　　European farm ministers have ended three weeks of negotiations with a deal which they claim represents genuine reform of the common agricultural policy(CAP). Will it be enough to kickstart the Doha world trade negotiations?

　　On the face of it, the deal agreed in the early hours of Thursday June 26th looks promising. Most subsidies linked to specific farm products are, at last, to be broken—the idea is to replace these with a direct payment to farmers, unconnected to particular products. Support prices for several key products, including milk and butter, are to be cut—that should mean European prices eventually falling towards the world market level. Cutting the link between subsidy and production was the main objective of proposals put forward by Mr Fischler, which had formed the starting point for the negotiations.

　　The CAP is hugely unpopular around the world. It subsidises European farmers to such an extent that they can undercut farmers from poor countries, who also face trade barriers that largely exclude them from the potentially lucrative European market. Farm trade is also a key feature of the Doha round of trade talks, launched under the auspices of the World Trade Organisation (WTO) in November 2001. Developing countries have lined up alongside a number of industrial countries to demand an end to the massive subsidies Europe pays its farmers. Several Doha deadlines have already been missed because of the EU