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问题 单项选择题

设关系模式Rm＜U，F＞，其中U＝｛H，I，J，K，L｝，若F=｛H→IJ，J→K，IJK→L，L→H，L→K｝，则F 的最小函数依赖集Fmin=｛ (1) ｝。关系模式R 的候选关键字有 (2) 个，R 属于 (3) 。

3（）

A．1NF

B．2NF

C．3NF

D．BCNF

答案

参考答案：A

阅读理解
阅读理解。
       SINA-In order to let people go out more easily during the 2008 Olympic Games, Beijing
is going to start a special bus line and seven more night bus lines. 40% of the taxis will be in
service for 24 hours. The subway will run longer hours, too. (December 27, 2007)
      YAHOO-An old man called Shen Yuanyan made five Fuwa toys with 6,000 pieces of
paper. It took him a few months to finish them. Mr. Shen will make another five bigger Fuwa toys
and send them to Beijing. (January 7, 2008)
       BAIDU-The Olympic Flame (圣火) has arrived in Beijing, showing that the Olympic
Games in China will soon begin. From today, the torch (火炬) will carry the Flame across the
world. (March 31, 2008)
      XINHUA-Yang Yang, a famous Chinese skater, received the Beijing Olympic torch
from a leader in Sanya, May 4, 2008. Yang ran the first 200 meters during the torch relay (接力) in
Sanya, the first leg in the Chinese mainland (大陆). (May 4, 2008)
1. ______ isn't mentioned in the news above.
[ ]
A. The bus
B. The taxi
C. The subway
D. The plane
2. The old man's Fuwa toys were made of ______.
[ ]
A. glass
B. paper
C. cotton
D. silk
3. The torch has carried the Flame across the world since ______.
[ ]
A. December 27, 2007
B. January 7, 2008
C. March 31, 2008
D. May 4, 2008
4. In the Chinese mainland, the first leg of the torch relay started in ______.
[ ]
A. Beijing
B. Chongqing
C. Shanghai
D. Sanya
5. There ______ of news about the Olympic torch relay here.
[ ]
A. is only one piece
B. are two pieces
C. are three pieces
D. are four pieces
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单项选择题

在MsgBox函数中哪一个参数是必须的

A．prompt

B．buttons

C．title

D．context
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