In a Cisco SDN， every element in the network acts as a point of defense. Which two best describethe features of Cisco SDN？ （）

A . Configuration revision number B . Configuration revision flag field C . Configuration revision reset switch D . Configuration revision database E . None of the other alternatives apply

A .  It is not supported for SSL connections. B .  It is not supported for non-SSL connections. C .  It can only be configured manually. D .  It has a maximum limit of 50，000 replicated connections.

A . A command that can be entered in any configuration mode. B . A command that supports all protocols. C . A command that is implemented in all IOS versions. D . A command that is set once and affects the entire router. E . A command that is available in every release of IOS.

A . origin B . router-ID C . AS-path D . local-preference E . next-ho

A . active / active using spanning tree B . active / active C . active / passive using spanning tree D . active / passive

A . to improve performance exclusively for SSL VPN applications B . to improve performance up to 300% for both IPsec and SSL VPN applications C . to improve performance for both IPsec and SSL VPN applications with IPsec encryption taking place in hardware D . to improve performance up to 200% for both IPsec and SSL VPN applications with encryption taking place in hardware E . to improve performance up to 300% for both IPsec and SSL VPN applications with SSL encryption taking place in hardware

A . Cisco IOS gateways provide services such as address translation and network access control for the devices on the network B . Cisco IOS gateways provide services such as bandwidth management and accounting C . Cisco IOS gateways provide media termination and signal translation between the public switched telephone network （PSTN） and IP networks D . Cisco IOS gateways provide zone management for all registered endpoints in the network

A . debug ip bgp updates B . debug ip tcp events C . debug ip bgp transactions D . debug ip tcp transactio

A .  0 B .  1 C .  2 D .  3 E .  4 F .  5

A . 正确 B . 错误

A . Cisco IOS gateways provide services such as address translation and network access control for the devices on the networl B . Cisco IOS gateways provide services such as bandwidth management and accounting C . Cisco IOS gateways provide media termination and signal translation between the public switched telephone network （PSTN） and IP networks D . Cisco IOS gateways provide zone management for all registered endpoints in the network

听力原文： In America, self-improvement is a national pastime. Every year, more and more Americans spend their leisure time trying to improve themselves one way or another. One popular form. of self-improvement is the search for physical fitness. Thousands of Americans who never exercised are now out on the streets jogging in fashionable running suits and expensive gym shoes. They boast of how many miles they nm each day and of how many pounds they lose each week. Others are turning to swimming, tennis, dance and the martial arts to improve their physical fitness. Instead of running around the park in the morning or evening, other Americans are studying yoga or meditating quietly in their homes. They are seeking to improve themselves by finding peace and quiet. Adult education is another form. of self-improvement. After a hard day's work, many Americans take evening courses at a kraal high school or a community college. There they can study a variety of subjects. Often these people am preparing to return to the job market or trying to qualify themselves for better jobs. For example, a mother busy raising her children might attend a night school to learn secretarial skills. A secretary might return to study accounting. Some retired people may go back for the education they missed at an earlier age. (30) A．Entertainment. B．Studying in a local college. C．Seeking physical fitness. D．Finding peace and quiet.

A．A.has been told B．B.has told C．C.have been told D．D.have told

set up set aside put away put up

此题为多项选择题。

A．prepend(self,elem) B．append(self,elem) C．insert(self,elem)+ D．forall(self,op)