在关系模型中,二维表的行称为______。
参考答案:元组
解析: 在关系型数据库中,用二维表来表示关系,二维表的表名即关系名,二维表的行称为关系的元组,二维表的列称为关系的属性。
Also found in Paragraph 1, what does "this case study" probably refer to
A.A case study the writer is to talk about.
B.Part of a textbook on politics.
C.What the author is going to write.
D.Washington's inability to fool anyone.
下列各组物质混合搅拌后,能形成溶液的是
A.面粉和水
B.汽油和水
C.蔗糖和水
D.食用油和洗涤剂