| A guard{{U}} (11) {{/U}}the prison shoe shop where Tom was working and took him to the prison office. There the guard told him he would be released. But Tom was too tired{{U}} (12) {{/U}}excitement. He had been in prison nearly{{U}} (13) {{/U}}and he had been sentenced to four years. True, he had expected to stay only about three months. He had a lot of friends and he had been sure they would help him. "Now, Tom," said the guard, "You’ll go out{{U}} (14) {{/U}}. Make a man of yourself. You’re not a bad fellow really. Stop breaking open safes and be{{U}} (15) {{/U}}"Hearing this, Tom was very happy. In fact, he had already had a plan for his future. But the most important thing for him was to have a big dinner. |
| A guard{{U}} (11) {{/U}}the prison shoe shop where Tom was working and took him to the prison office. There the guard told him he would be released. But Tom was too tired{{U}} (12) {{/U}}excitement. He had been in prison nearly{{U}} (13) {{/U}}and he had been sentenced to four years. True, he had expected to stay only about three months. He had a lot of friends and he had been sure they would help him. "Now, Tom," said the guard, "You’ll go out{{U}} (14) {{/U}}. Make a man of yourself. You’re not a bad fellow really. Stop breaking open safes and be{{U}} (15) {{/U}}"Hearing this, Tom was very happy. In fact, he had already had a plan for his future. But the most important thing for him was to have a big dinner. |
关系模式R(U,F)，其中U=W,X,Y,Z，F=WX→Y,W→X,X→Z,Y→W。关系模式R的候选键是（），（）是无损连接并保持函数依赖的分解。
关系模式R的候选键是（）关系模式及(U，F)，其中U=W，X，Y，Z，F=WX→Y，W→X，X→Z,Y→W。关系模式R的候选键是 (1) 、 (2) 是无损连接并保持函数依赖的分解。
1（）
[听力原文]
M：My car is in the repair shop again.
W：Maybe you should consider trading it in for a new one.
M: Do you know if the book shop is still open
W: Yes, it’s open till six.
M: Thanks a lot.
W: You are welcome.
我来回答:
