[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

    • Every man has moved into position and must remain silent and unobserved until the __ moment.

    Every man has moved into position and must remain silent and unobserved until th

  • 查看答案

    • Remember you must follow every step _ I've shown you.

    Remember you must follow every step _ Ive shown you.A. likeB. asC. overD. in

  • 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

    • 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

    • Every working person must pay income t____.2. The pirates buried the treasure____ on a desert island

    Every working person must pay income t____.2. The pirates buried the treasure___

  • 查看答案