【多选题】Regarding an IPsec security association (SA), which two statements are true?()
A.
IKE SA is bidirectional.
B.
IPsec SA is bidirectional.
C.
IKE SA is established during phase 2 negotiations.
D.
IPsec SA is established during phase 2 negotiations.
【单选题】The two fishermen saw ___________ in the sky while they were fishing by a river.
【判断题】当对机器周期进行计数时,定时计数器作为定时器用。
【单选题】如果单片机的晶振是12MHz,当定时计数器做定时功能时,定时器内部计数器,每计一个数的时间是( )
【单选题】Two fishermen saw ___in the sky while they were fishing by a lake.
【单选题】适航规章要求,化学氧气发生器应至少保证多长时间的供氧:
【简答题】适航规章要求,化学氧气发生器应至少保证多长时间的供氧() A12分钟 B30分钟 C60分钟 D90分钟
【单选题】___ took pictures of the two fishermen.
A.
The creatures in a UFO
B.
A driver of a police car