安全监控和人员位置监测系统主机及联网主机应当（）备份，连续运行。
A.双机热
B.单机热
C.一冷一热
参考答案：A
CIA三元组中的三个原则是（）
A.信心、一体化、可用性
B.一致性、完整性、身份验证
C.保密性、完整性、可用性
D.保密性、完整性、意识
What is the best guide for determining the proper scope of anchor chain to use for anchoring in normal conditions?（）
A.One shot of chain for every ten feet of water
B.One shot of chain for every fifteen feet of water
C.One shot of chain for every thirty feet of water
D.One shot of chain for every ninety feet of water
