Which conditions will normally cause a SART to operate in the active mode?()
A. It will respond only to interrogation by 9-Ghz radar signals
B. A SART will normally respond to interrogation from a searching vessel's radar if the radar antenna is at least 15 meters high
C. A SART will normally respond to interrogation from a searching aircraft's radar if the radar's output power is at least 10,000 watts and the aircraft is at a height of 3000 feet and within 30 nautical miles
D. All of the above
查看答案
查看公式中某一步的运算结果后,将数值结果恢复为公式需要按击Ctrl+`快捷键.
A. 正确
B. 错误
中途停止掘进时,支护应及时跟至工作面。
A. 正确
B. 错误