Which two statements are true about the roles in the Oracle database?()
A role can be granted to itself.
B. Roles are owned by the SYS user.
C. Roles can be granted to other roles.
D. A role cannot be assigned external authentication.
E. A role can contain both system and object privileges.
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柴油机调速器的功能中,能逐步调整油门负荷,保持转速的稳定,发生超车时断油停车,发生主要故障时自动切断供油。
A. 正确
B. 错误
假定芝加哥IMM交易的3月份到期的英镑期货价格为$1.5020/£,某银行报同一交割日期的英镑远期合约价格为$1.5000/£。应当如何操作才能谋取收益?试计算最大可能收益率。
佩带在多功能腰带上的单警装备,以腰带扣为准,从左到右依次为:手铐、对讲机、强光手电、警用装备包、警棍、手枪、催泪喷射器。
A. 正确
B. 错误