皮皮学,免费搜题
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搜题
【单选题】
不允许在关系中出现重复记录的约束可通过哪种约束实现
A.
外键约束
B.
非空约束
C.
检查约束
D.
唯一约束
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参考解析:
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举一反三
【单选题】指针p所指的字符串的存储长度为()
A.
12
B.
13
C.
14
D.
15
【简答题】EPON系统采用( )技术,实现( )传输。
【单选题】----She has two best friends. ----__of them is in the country.
A.
All
B.
Both
C.
No one
D.
Neither
【单选题】指针p所指的字符串的长度为( )。 char *p="Hello\tWorld!” ;
A.
12
B.
13
C.
14
D.
15
【单选题】Although she is only 17 years old, she _________ drugs for two years.
A.
Addicts
B.
has addicted to
C.
has addicted
D.
has been addicted to
【简答题】She has been given three free tickets for tomorrow’s concert and she ______ there with two of her best friends. A.has gone B.is going C.has been D.went
【单选题】指针所指向的字符串的长度为__ __________。
A.
ar *s=”\t\’Name\\Address\n” ;
B.
19
C.
18
D.
15
E.
17
【单选题】下面哪种命令是无边框的盒子命令?
A.
fbox
B.
mbox
C.
framebox
D.
boxed
【简答题】EPON系统采用()技术,实现单纤双向传输。
【判断题】EPON系统采用WDM技术,实现单纤双向传输
A.
正确
B.
错误