在关系的规范化过程中，消除了哪些依赖后，1NF变成了3NF
A．部分依赖和传递依赖
B．完全依赖和传递依赖
C．完全函数依赖
D．部分函数依赖
参考答案：A
解析： 规范化程度有四级。第一范式(1NF)要求的条件是元组中的所有分量必须是不可分的数据项；第二范式(2NF)要求关系模式R∈1NF，且每一个非主属性完全函数依赖于码，即不允许非属性对码的部分函数依赖；第三范式(3NF)要求关系模式 R∈2NF，且每一个非属性都不传递依赖于码。因此在关系的规范化过程中，消除了部分依赖和传递依赖，1NF会变为3NF。
In this early day of the United States of America, it wasn’t easy ____ from one town or city to _____. There were no trains. Of course, and the roads were very poor. If a man wanted to go from one place to another, he often _____ a horse. And because the roads were bad, he sometimes got very dirty. One day a man came into a hotel in a little country town. His clothes were very dirty, and he looked very tried. “ Do you have a room here _____ me?” he asked. The hotel man at the desk thought, “ I don’t want this man ____ here. He’s too dirty for my hotel.” “ I’m sorry.” He said. “ We don’t have any ___ rooms. There’s a small hotel down the street. You can ask there.” Soon an important-looking man having fine clothes came into the hotel. “ I’ve come to see Mr. Jefferson,” he said. “ Mr. Jefferson?” “ Yes, Vice-president(副总统) Jefferson. We planned to meet here.” The hotel man was ____ “ A man _____ dirty clothes was just here. I thought he was a farmer, and sent him to another hotel a few minutes ago.” The hotel man _____ the Vice-president’s room in the other hotel. “ Oh, Mr. Jefferson,” he said, “ I’m very sorry I thought you were a farmer. We have a room at our hotel. Please come back.” “ No.” said Mr. Jefferson, “ If there’s no room for a farmer, there’s no room for the Vice president, _____.”
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