CCNA系列认证
单选题What is the objective of Diffie-Hellman？（）A used to verify the identity of the peerB used between the initiator and the responder to establish a basic security policyC used to establish a symmetric shared key via a public key exchange processD used for
题目
used to verify the identity of the peer
used between the initiator and the responder to establish a basic security policy
used to establish a symmetric shared key via a public key exchange process
used for asymmetric public key encryption
相似问题和答案
第1题：
A.支持动态机制
B.支持开放式的动态绑定，简单化交互式用户接口架构
C.Objective-C包括命名空间机制
D.常见的编译时性能优化方法不能用于Objective-C
第2题：
下面哪个属于对称加密算法
A、Diffie-Hellman算法
B、DSA算法
C、RSA算法
D、DES算法
第3题：
What is the author’s attitude toward “old wives tales” in the text?
A. Subjective B. Objective C. Dissatisfied D. Curious
第4题：
A. document power and UPS availability
B. to integrate routing and switching components
C. create a design specification document
D. document the customer‘s current and future technology projects
第5题：
The result of the human cognition of the objective world is called concept.()
第6题：
听力原文：M: The primary objective of financial reporting is to provide information useful for making investment and lending decisions.
W: The information must be relevant, reliable, and comparable.
Q: What is the primary objective of financial reporting?
(15)
A．To make investment.
B．To record data.
C．To provide useful information.
D．To understand some basic accounting principles.
解析：根据男士的说法，财务报告的作用在于为投资决策和筹资决策提供有用的信息。
第7题：
Business report should be objective and factual.()
第8题：
A、To make money
B、To develop skills
C、To win
D、To make friends
第9题：
Consider the query:Mysql＞ SET @run = 15;Mysql＞ EXPLAIN SELECT objective, stage, COUNT (stage)FROM iteminformationWHERE run=@run AND objective=’7.1’GROUP BY objective,stageORDER BY stage;The iteminformation table has the following indexes;Mysql＞ SHOW INDEXES FROM iteminformation:This query is run several times in an application with different values in the WHERE clause in a growing data set.What is the primary improvement that can be made for this scenario?（）
A.Do not pass a user variable in the WHERE clause because it limits the ability of the optimizer to use indexes
B.Add an index on the objective column so that is can be used in both the WHERE and GROUP BY operations
C.Drop the run_2 index because it has caused a conflict in the choice of key for this query
D.Execute the run_2 index because it has caused a conflict in the choice of key for this query
E.Add a composite index on (run,objective,stage) to allow the query to fully utilize an index
第10题：
简述Objective-C的优缺点。
正确答案: objc优点：
1）. Cateogies
2）. Posing
3）. 动态识别
4）.指标计算
5）.弹性讯息传递
6）.不是一个过度复杂的 C 衍生语言
7）.Objective-C 与 C++ 可混合编程
objc缺点：
1）.不支援命名空间
2）.不支持运算符重载
3）.不支持多重继承
4）.使用动态运行时类型，所有的方法都是函数调用，所以很多编译时优化方法都用不到。（如内联函数等），性能低劣。