世界上的各个外汇市场在营业时间上相互交替,形成一种前后继起的循环作业格局,这是指外汇 发布时间:2017-06-27 00:08 │ 来源:www.tikuol.com 题型:单项选择题 问题: 世界上的各个外汇市场在营业时间上相互交替,形成一种前后继起的循环作业格局,这是指外汇市场的( )。A.流动性B.风险性C.空间统一性D.时间连续性
题型:单项选择题 What is the candidate key of a relational database ( )A.Fields from multiple tables that are used for sorting recordsB.A set of fields in a table used to identify a record uniquelyC.A field with a constraint placed on itD.A set of fields that have no data in them 查看答案