When you turn on the fast time constant (differentiator) control of a radar it will().
A. enhance weak target echoes and brighten them on the PPI
B. reduce clutter over the entire PPI by shortening the echoes
C. only suppress weak targets to a limited distance from the ship (sea clutter)
D. reduce the beam width to provide a map-like presentation for navigatio
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联苯炉报警灯电源电压、上下联络及油槽报警灯电源电压分别是()。
A. DC24DC24DC24V
B. DC24AC220DC24V
C. DC24AC220AC220V
D. AC220AC220AC220V
在船舶灭火指挥决策中,组织决策只能在灭火战斗之前进行。
A. 正确
B. 错误
人们应当复古倒退,回到可再生的原料,由此出发去加工合成系列产品。
A. 正确
B. 错误
触电时通过人体的电流强度取决于().
A. 触电电压
B. 人体电阻
C. 触电电压和人体电阻
D. 都不对