安全保护距离safe protection distance

At a safe distance, they listened to the explosions and watched smoke ________ i

[名词解释] 防护（protection against）与保护（protection for）

[名词解释] Vector－distance矢量距离

[名词解释] 外推距离 extrapolation distance

[名词解释] 保护系统 protection system

[名词解释] 线间距离 distance between tracks

[单选题]RIP的管理距离（Administrative Distance）是（）A .90B .100C .110D .120

[名词解释] 线性外推距离 linear extrapolation distance

[名词解释] 安全端 safe end

[名词解释] 安全停堆 safe shutdown