填空题

阅读下面这篇短文，短文后有2项测试任务：(1)第23～26题要求从所给的6个选项中为规定段每段选择1个正确的小标题；(2)第27～30题要求从所给的6个选项中选择4个正确选项，分别完成每个句子。
Computer Security
1. As the business sector, and indeed all of our society, becomes more dependent on computers, concern about computer security grows. According to Business Week, roughly $1 trillion is transferred every day via computer networks. Yet a knowledgeable person can, with relative ease, access a computer system and cause serious damage. Estimates of the annual cost of computer crime range from $ I billion to $ 2 billion.
2. One of the most recent computer problems firms face is called a "computer virus". A virus is a type of computer program that is intentionally hidden in other computer programs. When a program with a virus comes into contact with other programs, the virus attacks the other programs. Some viruses can destroy every bit of information in a computer. Businesses also fact the problem of losing highly confidential data to computer hackers. These individuals break into computer systems and steal information or damage programs.
3. Computer viruses and computer hackers present a huge potential risk to firms. They have shut down entire computer systems in some large companies.
4. Fortunately, business firms can now obtain insurance coverage for losses from computer crime. Although some policies specifically cover computer viruses, many others were drafted before computer viruses became a problem. These policies generally insure all risks of direct physical loss or damage, unless something is specifically excluded. The issue then becomes whether or not the damage caused by a computer virus is a physical loss. In some cases, insurance companies have maintained that information lost on a computer is not physical property and thus is not covered by a traditional all-risk policy.
5. Many insurance companies are beginning to use policy language that deals specifically with the loss of computer information. In this way, the insured understands what is covered, and the insurance company can avoid a large, unexpected loss. Courts have held that information stored on the computer is tangible (切实的) property in tax cases. In property insurance cases, they may handle the destruction of computer information the same way. Destruction of valuable information, therefore, could result in a catastrophic loss that is covered under an all- risk policy unless there is limiting language.
A. Fatalness from viruses and hackers
B. Two primary dangerous factors: virus and hacker
C. How the viruses and hackers destroy our computers the loss of computer information
D. Attitudes towards
E. The best way to protect our computers
F. The policies about the viruses
Paragraph 4 ______.