单项选择题
A.voltage B.current C.power D.frequency
() is used to produce electric power.A.An alternatorB.f...
单项选择题() is used to produce electric power.
A.An alternator B.fresh water generator C.A compressor D.A clarifier
The system will include various () such as low tank lev...
单项选择题The system will include various () such as low tank level alarms and remote operation of tank outlet valves in the events of a fire.
A.Switches B.panels C.alarm units D.safety devices
Electric insulation is made of organic substances and s...
单项选择题Electric insulation is made of organic substances and so gradually () with age.
A.deteriorates B.increases C.are fouled D.becomes better