变压器差动保护为了减小不平衡电流,常选用一次侧通过较大的短路电流时铁芯也不至于饱和的TA,一般选用()
A.0.5级
B.TPS级
C.D级
D.0.2级。
参考答案:C
The helm command PORT TWENTY means().
A.change course twenty degrees to the left
B.put the rudder left twenty degrees
C.put the rudder hard left for the first twenty degrees of swing
D.put the rudder left twenty degrees and then ease back as the vessel starts swinging
以下不是多轴飞行器优点的是()
A.构简单
B.成本低廉
C.气动效率高