在数据库技术中，实体-联系模型是一种()。
A．概念数据模型
B．结构数据模型
C．物理数据模型
D．逻辑数据模型
参考答案：A
解析：概念模型是对信息世界建模，所以概念模型应该能够方便、准确地表示信息世界中的常用概念。概念模型的表示方法很多，其中最为常用的是P．P．Chen于1976后提出的实体-联系方法。该方法用E-R图来描述现实世界的概念模型，称为实体-联系模型(Entity-Relationship Model)简称E-R模型。
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| A woman saw three old men sitting outside. She said, "I don' t think I know you, but you must be very hungry. Please come in and have something to 1 ." "We don't go into a house 2 ," they answered. "Why is that?" she asked. One of the old men said, "His name is Wealth (财富) this is Success, and I am Love. Now go in and 3 with your family which one of us you want in your house." The woman went in and told her family all that happened. She said, "Let's invite Wealth. We have been so 4 ." Her husband disagreed, "My dear, why don't we invite Success? Don't you want me to be a successful man?" Then her daughter asked, "Would it be 5 to invite Love? Our life will then be filled with love!" In the end, the family decided to take the 6 advice. So the woman went out and asked, "Which one of you is 7 ? Please come in and be our guest." Love got up and started walking to the house. The other two also got up and 8 him. Surprised, the lady asked Wealth and Success, "I 9 invite Love. Why are you coming along?" The two old men answered, "If you invited Wealth or Success, the other two would have to 10 , but as you invite Love, wherever he goes, we go with him. Where there is Love, there is Wealth and Success." | |||
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