When oily water separator is operating, which measure （） is wrong.

A、pay attention to operating parameters

B、renew and clean separating units in time

C、check oil level in separator to prevent overload

D、check separating effect, if it is bad, flush with large capacity water pump

Which of the following problems will occur if the internal drain at either end of a hydraulic, two-way, spool-type directional control valve cylinder were to become plugged?（）

A、The reservoir would become vapor bound

B、The valve would be placed in hydraulic lock

C、The spring loaded relief ports would open

D、The buffering chambers would be unable to function

To safeguard the operator and other personnel working on or near a hoisting operation which of the following precautions should be observed?（）

A、Keep a load on the hoist until all personnel are finished working

B、Set the load on a movable dolly when transportation may be needed

C、Have one man keep a hand on the load to steady it

D、Insure that the lifting gear capacity is not exceeded

The demisters installed in a flash-type evaporator serve to （）

A、deaerate the first effect distillate

B、filter the condensed flash vapors

C、deaerate the first and second effect distillate

D、remove small water droplets entrained in the flashed vapor

The load between two steam-driven alternators operating in parallel may be adjusted by varying （）

A、the speed of the alternators

B、the field strength of the machines

C、the power factor of the alternators

D、steam supply to the prime movers

Basically the bedplate consists of two （）, which run the length of the engine.

A、longitudinal girders

B、transverse girders

C、fore girders

D、aft girders