【单选题】指挥自动化系统,又称为C4ISR 系统。其中“S”的含义是指
【单选题】自动化指挥系统,是用电子计算机将指挥、控制、通信和情报各分系统紧密联在一起的综合系统。也称(C4ISR系统)。其中,C4指的是Command(指挥)、()、Communication(通信)、Computer(计算机);I指的是Intelligence(情报);S指的是Surveillance(监视);R指的是Reconnaissance(侦察)。
【简答题】I can sell things in a shop. I am a shop a_____.
【简答题】Listen to the following talk and fill in the blanks with missing words. The talk is given twice. Jones is buying some things at the hardware store( 五金店 ). The storekeeper has many bicycles in the stor...
【单选题】听力原文:M: You look happy. Did you sell lots of things at the store today? W: No. I bought something. It was a great deal. M: So what is it? W: A laptop computer. M: Really? That's great. They are really...
A.
She is a software engineer.
B.
She is an after-sale service worker.
C.
She works as a salesclerk.
D.
She is hunting for a job.
【简答题】指挥信息系统在西方发达国家称之为C4ISR系统,其中S是( )系统的简称。
【多选题】关于静电场的高斯定理,下列说法正确的是
B.
若高斯面上各点的D为零,则面内自由电荷及极化电荷总量分别为零
C.
对于 各向同性均匀 线性电介质,若高斯面上各点的E为零,则面内自由电荷及极化电荷总量分别为零。
D.
若高斯面内的自由电荷总量为零,则面上各点的D必为零
【单选题】关于静电场的高斯定理,下列说法正确的是 ( )
A.
闭合曲面上各点的电场强度都为零时,曲面内一定没有电荷
B.
闭合曲面上各点的电场强度都为零时,曲面内电荷的代数和必定为零
C.
闭合曲面的电通量为零时,曲面上各点的电场强度必定为零
D.
闭合曲面的电通量不为零时,曲面上任意一点的电场强度都不可能为零