The unit of electrical resistance is the （）

A、opposes any change in the applied voltage B、opposes any change in the current flow through the circuit C、aids any changes in the applied voltage D、aids any changes in the current through the circuit

A . length increases B . cross-sectional area increases C . temperature increases D . percent of metallic purities increase

A、bridge control panel B、disconnect links C、governor relay box D、main switchboard

A . balance B . not balance C . be more than D . be less tha

A . Class "A" B . Class "B" C . Class "C" D . Class "D&quot

A . Carbon dioxide B . Distilled water C . Fresh water D . Salt water

A . When heated, it will move proportional to the amount the metal has lengthened or expanded B . The pointer associated with the pyrometer scale can be made to also measure engine RPM C . It can be utilized in exhaust manifolds and heat exchangers interchangeably D . It can indicate temperature at a distant point from the source heat

A . low voltage trip B . reverse power trip C . damage to windings D . excessive exhaust temperature

A . develop torque B . generate high voltages C . produce a magnetic field D . generate high electrical resistance

A . Frequency meter B . Ohmmeter C . Induction voltage regulator D . Current transformer governor

A . to make the United States gain time to arm itself B . to actually help the aggressors by making clear that the United States would not intervene C . to get the United States involved in the war D . to prevent the United States form being dragged into the war

A . low voltage trip to trip B . reverse power trip to trip C . damage to windings D . excessive exhaust temperature

A.is good for long term preserving since most insulation is organic and contains some amount B.lowers the insulation value and is a common cause of fault grounds in idle machines C.will enhance insulation resistance only if it is no salt D.reduces the amount of current supplied or drawn by the machine so horsepower is limited

A．legislative. B．executive. C．judicial. D．party.

A. the Prime Minister． B. the Speaker of the House of Lords． C. the Speaker of the House of Commons． D. the Queen．

A．It has been a leader in the global economy. B．It's hard for the United States to keep the original economic position forever. C．The United States owns others a lot of money. D．Its economy will grow more than any other country in the world over next two years. 此题为多项选择题。

A．gives by far the most power to Congress B．gives by far the most power to the president C．tries to give each branch enough power to balance the others D．It was drafted by the king