关系模式R中若没有非主属性,则( )A.R属于2NF,但R不一定属于3NF B.R属

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问题:

关系模式R中若没有非主属性,则( )

A.R属于2NF,但R不一定属于3NF

B.R属于3NF,但R不一定属于BCNF

C.R属于BCNF,但R不一定属于4NF

D.R属于4NF

考点:计算机等级考试数据库技术全国计算机等级考试三级数据库技术真题2004年9月
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单词拼写 (共10小题;满分5分,每题0.5分)

根据所给中文或首字母写出相应单词的正确形式(每格一词).

小题1:Nowadays, there’re more and more family problems _________(产生)from lack of   communication.

小题2:They supposed that their theories could explain conclusively the many natural __________(现象).

小题3:With the flight d__________ by the storm, the passengers had to stay at the airport for the night.

小题4:A good night's sleep can be b__________ to one's health.

小题5:Now we all know it is necessary and important to pass strict law to forbid d          driving,     as lots accidents happen every year.

小题6:To be on time is important to Americans. The ideal person is p          and is considerate of     other people’s time.

小题7:_______________(不幸) for him, he had his leg broken in the football match. What’s worse was     that his puppy love ended up in failure.

小题8:Some people maintain that watching violence on TV is one of the major causes of              (好斗的) behavior and crime in society.

小题9:___________ (统计数据) show that women live longer than men.

小题10: Dr. Johnson ___________ (承担) the task of writing an English dictionary last year.

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工程师对进度计划予以确认或者提出修改意见,并不免除( )施工组织设计和工程进度计划本身的缺陷所应承担的责任。

A.发包人

B.监理人

C.承包人

D.项目经理

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在吸收塔操作中,为什么要将稳定汽油打入吸收塔内?

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江南丝竹

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()是数组的数组,它内部每个数组的长度可以不同,就像一个锯齿形状。

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