Questions 53 to 57 are based on the following passage: The Internet can make the news more democratic, giving the public a chance to ask questions and seek out facts behind stories and candidates, according to the head of the largest US on-line service. ’But the greatest potential for public participation is still in the future,’ Steven Case, chairman of America On-line, told a recent meeting on Journalism and the Internet sponsored by The Freedom Forum, though some other speakers say the new technology of computers is changing the face of journalism, giving reporters access to more information and their readers a chance to ask questions and turn to different sources. ’You don’t have to buy a newspaper and be confined to the four comers of that paper anymore.’ Sam Meddis, on-line technology editor at USA Today, observed about the variety of information available to computer users. But the speakers noted the easy access to the internet also means anyone can post information for others to see.’Anyone can say anything they want, whether it’s right or wrong.’ said Case. Readers have to determine for themselves who to trust. ’In a world of almost infinite voices, respected journalists and respected brand names will probably become more important, not less,’ Case said. ’The internet today is about where radio was 80 years ago, or television 50 years ago or cable 25 years ago, ’he said. But it is growing rapidly because it provides people fast access to news and a chance to comment on it. The correct order for the appearance of the four technologies is () .
A. internet-cable-television-radio
B. radio-cable-television-internet
C. radio-television-cable-internet
D. television-radio-cable-internet
开-闭原则(Open-Closed Principle, OCP)是面向对象的可复用设计的基石。开-闭原则是指一个软件实体应当对 (37) 开放,对 (38) 关闭;里氏代换原则(Liskov Substitution Principle, LSP)是指任何 (39) 可以出现的地方, (40) 一定可以出现。依赖倒转原则(Dependence Inversion Principle, DIP)就是要依赖于 (41) ,而不依赖于(42) ,或者说要针对接口编程,不要针对实现编程。 (37)处填()。
A. 修改
B. 扩展
C. 分析
D. 设计
设有学生实体Students(学号,姓名,性别,年龄,家庭住址,家庭成员,关系,联系电话),其中“家庭住址”记录了邮编、省、市、街道信息;“家庭成员,关系,联系,电话”分别记录了学生亲属的姓名、与学生的关系以及联系电话。学生实体Students中的“家庭住址”是一个(52)属性;为使数据库模式设计更合理,对于关系模式Students(53)。 (53)处填()。
A. 可以不作任何处理,因为该关系模式达到了3NF
B. 只允许记录一个亲属的姓名、与学生的关系以及联系电话的信息
C. 需要对关系模式Students增加若干组家庭成员、关系及联系电话字段
D. 应该将家庭成员、关系及联系电话加上学生号,设计成为一个独立的实体