参考答案:ABD
两个实体之间的联系实际上是实体集合的函数关系,这种函数关系可以有下面几种,即一对一的联系、一对多(或多对一)的联系和多对多的联系;概念模型便于向各种模型转换。由于概念模型不依赖于具体的数据
第34题: [简答题]Part 1Dancing
Do you like dancing
When do people in your country dance
Do young people in your country like old-style dancing (or, traditional dancing)
Have you ever learned to dance
When was the last time you danced
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