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【单选题】
（ 5 ）下列关于信息认证的叙述中，哪一项是不正确的？A.
）验证体制中存在一个完成仲裁、颁发证书等功能的可信中心
B.
）数字签名的签名者事后不能否认自己的签名
C.
）消息认证要检验的内容包括消息的序号和时间性
D.
）对密码系统的主动攻击是通过分析和识别截获的密文完成的
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【简答题】公司行政办某日收到的邮件很多,其中包括寄给总经理的注明“急件”的函件、寄给人事部经理的私人包裹、若干封商业信函和私人信件以及报刊和小册子等印刷材料。请按接收邮件的工作程序进行规范操作。
【判断题】Given square matrices A and B. Then A is row equivalent to B if and only if A is column equivalent to B.
A.
正确
B.
错误
【单选题】In the country of ______, Gulliver was given three kinds of meat: a square of beef, a triangle of chicken, and a circle of lamb.
A.
Lilliput
B.
Houyhnhnm
C.
Luggnagg
D.
Laputa
【简答题】A．33 pounds per square inch. B．14.7 pounds per square inch. C．600 pounds per square inch. D．280 pounds per square inch.
【单选题】The area of Chicago is ______.
A.
228 square miles
B.
32 square miles
C.
23 square miles
【简答题】If a square prism has an edge of 5 inches, what is the volume of the square?
【单选题】The sides of a square are 3 cm long. One vertex of the square is at (2,0) on a square coordinate grid marked in centimeter units. Which of the following points could also be a vertex of the square?
A.
(-4,0)
B.
(0,1)
C.
(1,-1)
D.
(4,1)
E.
(5,0)
【单选题】Quancheng Square is one of _____ largest in China, _____ second to Tiananmen Square. [ ]
A.
the; the
B.
the: a
C.
/; the
D.
the; /
【简答题】阅读理解。 Square Dance ABC HOME PAGE Square Dance ABC is an exciting new way to practice square dancing. Enjoy a funny, easy beginner's square dance, with no experience needed. There are three different d...
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