如果一个关系中每个属性都是不可再分的,则该关系属于。
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在关系模式R(U,F)中,Y为非主属性,对任何非平凡的函数依赖X→Y,X均包含码,则R属于 。
对于一个规范程度不高的关系模式,可通过 方法转换到更高范式。
Choose the best answer to each question.What is the thesis statement of the passage?
A. The Internet in 2050 may be everywhere.
B. The Internet in 2010 will made it easy for the general user to access it.
C. The Internet in history.
All of the statements are the supporting ideas of the central theme EXCEPT______
As the Internet develops, privacy will disappear.
B. Wireless networks will be the primary access point for most devices.
C. As technologies go, the Internet is still a baby.
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