99色精品-9色在线-99色在线-99色视频 国产欧美日产一区二区三区_亚洲精品亚洲人成在线观看_四虎在线精品永久观看_免费一级a一片久久精

單項選擇題

Which method should be used to warm up the pump turbines prior to discharge().

A.Lock the turbine rotor and slowly bleed in steam until operating temperature is reached
B.Run the pump at high speed with the discharge valves closed
C.Run the turbine at slow speed with the pump disconnected
D.Shut the discharge valve and run the pump at slow speed

微信掃碼免費搜題