听力原文: My friend Leo makes up weak and poor excuses whenever there's something he doesn't want to do. Just two weeks ago, he was at my house when he decided he didn't want to go into work. He called his boss and said he had to get a new set of tires put on his truck. Then he sat down and watched TV with me. Not only had he lied, but his excuse wasn't a very convincing one. Another time he canceled a date with his girlfriend at the last minute, telling her he had to get a new battery for his truck.
She was angry and refused to go out with him again until he apologized. Last weekend, Leo offered the poorest excuse yet. He'd promised he'd help me move some furniture from my parents' house to my new apartment. He was supposed to bring his truck over about 8 o'clock Saturday morning. I waited and then called and left a message on his machine. About 11:30, he called and said he was sorry but he'd been getting a new set of tires put on his truck. I guess he'd forgotten he used the same excuse when he called his boss from my house. I think I need a new set of friends. I'm beginning to get tired of Leo's excuses.
Questions:
What does the speaker tell us about her friend Leo?
What did his girlfriend do when Leo canceled the date with her at the last minute?
What favor did the speaker ask Leo to do last weekend?
(30)
A.He will betray even his best friends.
B.He is able to make up good excuses.
C.He will lie whenever he wants.
D.He tries to achieve his goal at any cost.
第1题
在E-R图中,对于1:n的联系,在转换成关系模式时所采用的处理方法是()。
A.必须单独作为一个关系
B.要转换成两个关系
C.与一端对应关系模式合并
D.与n端对应关系模式合并
第2题
下列有关E-R模型向关系模型转换的叙述中,不正确的是()。
A.一个实体类型转换成一个关系模式
B.一个m:n联系转换为一个关系模式
C.一个1:1联系可以转换为一个独立的关系模式,也可以与联系的任意一端实体所对应的关系模式合并
D.一个1:n联系可以转换为一个独立的关系模式,也可以与联系的任意一端实体所对应的关系模式合并
第3题
A.一个实体类型转换成一个关系模式
B.一个m:n联系转换为一个关系模式
C.一个1:1联系可以转换为一个独立的关系模式,也可以与联系的任意一端实体所对应的关系模式合并
D.一个1:n联系可以转换为一个独立的关系模式,也可以与联系的任意一端实体所对应的关系模式合并
第4题
A.一个实体类型转换成一个关系模式
B.一个m:n联系转换为一个关系模式
C.一个1:1联系可以转换为一个独立的关系模式,也可以与联系的任意一端实体所对应的关系模式合并
D.一个1:n联系可以转换为一个独立的关系模式,也可以与联系的任意一端实体所对应的关系模式合并
第5题
(56 )下列有关 E-R 模型向关系模型转换的叙述中,不正确的是
A )一个实体类型转换成一个关系模式
B )一个 m : n 联系转换为一个关系模式
C ) 一个 1 : 1 联系可以转换为一个独立的关系模式 , 也可以与联系的任意一端实体所对应的关系模式合并
D ) 一个 1 : n 联系可以转换为一个独立的关系模式 , 也可以与联系的任意一端实体所对应的关系模式合并
第7题
A.更高级别范式
B.原有函数依赖关系
C.减少冗余
D.达到4NF
第8题
A.删除了不该删除的数据
B.应该删除的数据没有删除
C.无法删除应该删除的数据
D.无法恢复删除的数据
第9题
A.2NF
B.3NF
C.BCNF
D.4NF
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