The single letter G，sent by an icebrea

1、The African way of communication sent

The African way of communication sent messages______.A in a special wayB over a very short distanceC by a musical instrumentD at a rather slow speed

2、The energy consumed by an AC motor, as

The energy consumed by an AC motor, as strictly reactive power, is （）Aused to do mechanical workBused to establish the magnetic field of the motorClost as heat generated by the windingsDlost in doing work to turn the motor itself

3、An icebreaker may use the code letter

An icebreaker may use the code letter “K” to remind ships of their obligation to listen continuously on their radio. This signal may be made by any of the following EXCEPT（）.Asound signalBlight signalCvisual signalDradiotelephone

4、The color of the signal flare sent up

The color of the signal flare sent up by a submarine about to surface due to an emergency condition within the submarine is（）.AgreenBredCwhiteDyellow

5、Assuming that an IP packet is sent fro

Assuming that an IP packet is sent from a source address in VLAN1 to a destination address in VLAN2 through a layer-3 switch, which part of the packet will be changed?（）A Layer 2 TTLB Layer 3 TTLC Layer 3 source addressD Layer 3 destination addre

6、The heat that is produced by burning g

The heat that is produced by burning garbage can be used to______.A make electricityB make energy sourceC boil waterD save coal