题目内容：

    Since May 12, a computer virus named WannaCry has infected (感染) more than 300,000computers in over 150 countries, according to Reuters.

Wannacry is spread by using a weakness in Microsoft's Windows operating system. Once the virus gets into the computer, it locks all the papers and asks the user for money to unlock them. At first, it asks for $300, but if the user doesn't send the money in 72 hours, the price doubled. Papers are locked forever if the user doesn't pay in seven days.

The virus has brought bad results. For example, in the UK, the virus left the country’sNational Health Service in a mess. Some hospitals had to cancel patient appointments(预约), reported The Telegraph. In China, the virus has hit thousands of computers, according to Qihoo360. One of the most hard-hit groups in China were university users. Many students' graduation papers were locked. They felt nervous and frightened. Also many gas stations were seriously hit, and the payment system didn’t work.

WanaCry is the latest example of the cyber security(网络安全) problem. Matthew Hickey, who set up the security company Hacker House, said, "The attack is not surprising. It shows that many organizations do not use updates(更新) fast enough. According to a survey, nearly half of the people said, “We are not satisfied with the way software updates work.”

As China Daily wrote, “We can’t completely protect our computers against these kinds of viruses, as this cat and mouse game will continue forever. The best choice for most users is to take care online and always install(安装)software updates.”

1.What is WannaCry?

A.A video game. B.A computer software. C.A computer virus. D.A TV programme.

2.If your papers are locked by Wannacry, how much do you need to pay if you don’t send the money in 72 hours?

A.$150. B.$300. C.$600. D.$900.

3.According to the passage, the writer shows the bad results by ________.

A.giving reasons B.giving examples C.comparing computers D.comparing numbers

4.From the last two paragraphs, we can know that________.

A.Matthew Hickey thinks the attack on computers is very surprising

B.all the people are pleased with the way software updates work

C.the computers can be completely protected against these viruses

D.we should take care online and update software fast enough