问题
填空题
在关系模式R中,如果X→Y,并且对于X的任何一个真子集X’,都有
,则称Y对X______函数依赖。
答案
参考答案:完全
在关系模式R中,如果X→Y,并且对于X的任何一个真子集X’,都有
,则称Y对X______函数依赖。
参考答案:完全
Robeson was born in a very poor family. At seven, he had to pick coal in a deserted mine near his home, and then he sold__36__he had picked and earned a few coins to help his parents. He had__37__schooling, for being so poor, how could they__38__school fees? When he was fifteen, he worked__39__a servant in a school. Looking at other children studying in the classroom,he felt__40__for himself. How he__41__to have the same chance! He decided to study by__42__.In the daytime, after the sweeping and cleaning was over, he__43__stand by the window outside the classroom trying to catch what the teacher said. At night, he tried his best to remember what he__44__during the day. He worked__45__hard at his lessons that he sometimes had just three or four hours to sleep. The more he learned, the greater__46__he showed in his lessons. A math teacher discovered him and came to like this diligent boy and__47__him to sit at the back of the class. In one exam, he was the__48__one in the whole school who reached the highest grade. He would have been given the scholarship if he__49__a regular student of the school. Robeson__50__through six long years with his study of math and wrote several articles which captured the__51__of some university professors. They admired his talent__52__his diligence. To give him a good chance, they hired him as a librarian and__53__him free guidance. Robeson felt__54__, for he was sure that before him there was a broad road__55__success.
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