[单选题]

Every value in arelation must be().

A．composite(复合的)and single-valued

B．single-valued

C．notnull and single-valued

D．simple and single-valued

参考答案与解析：

相关试题

At expiration, the value of a call option must equal:

[单选题]At expiration, the value of a call option must equal:A.The larger of the st

  • 查看答案

    • The instrumental panel of the generator must( )clean every day.

    [单选题]The instrumental panel of the generator must( )clean every day.A.keepB.to k

  • 查看答案

    • Every government that refuses to meet the needs of its people must accept the( )

    [单选题]Every government that refuses to meet the needs of its people must accept t

  • 查看答案

    • The control panel of the steam turbine must( )clean every day.

    [单选题]The control panel of the steam turbine must( )clean every day.A.keepB.to ke

  • 查看答案

    • Firms claiming GIPS compliance must make every reasonable effort to provide a compliant presentation

    [单选题]Firms claiming GIPS compliance must make every reasonable effort to provide

  • 查看答案

    • As early as 1647 Ohio made a decision thatfree, tax-supported schools must be established in every t

    [单选题]As early as 1647 Ohio made a decision thatfree, tax-supported schools must

  • 查看答案

    • Arelation(from the relational database m

    [单选题]Arelation(from the relational database model)consistsof(由⋯⋯组成)a set of tuples(元组),whichimplies(意味着)that().A．all tuples in a relation must be distinct(独一无二的)B．every relation has a key(键)C．all of the aboveD．for any two tuples,the values associated with

  • 查看答案

    • Passage Four Every culture and every cou

    [单选题]Passage FourE．very culture and every country in the world celebrates New Year, but not everyone does it the same way. The countries in North America and Europe welcome New Year on January the first. This practice began with the Romans in the Middle E

  • 查看答案

    • Price-to-book value ratios are most appropriate for measuring the relative value of a:

    [单选题]Price-to-book value ratios are most appropriate for measuring the relative

  • 查看答案

    • This plan must be realized by( )

    [单选题]This plan must be realized by( )A.no meansB.all meansC.meansD.any mean

  • 查看答案