why is quick closing valves important to in engine room machineries ?how are they operated ?

[单选题]The closing of the exhaust valves used on a modern, large, low-speed, main propulsion diesel engine may be directly provided by_______.A．large conical springsB．compressed air pressureC．hydraulic pressureD．exhaust gas pressure

[主观题]Why is tolerance important?___________

[单选题]Why are researches on parrots important according to the passage?A． The Trust shows great concern for the programme.B． We need to know more about how to preserve parrots.C． Many people are interested in collecting parrots.D． Parrots’ intelligence may

[单选题]Someone says, "Time is money." But I think time is ___1___ important than m

[单选题]Someone says, "Time is money." But I think time is ___1___ important than m

[单选题]Someone says, "Time is money." But I think time is ___1___ important than m

[单选题]Someone says, "Time is money." But I think time is ___1___ important than m

[单选题]Someone says, "Time is money." But I think time is ___1___ important than m

[单选题]Someone says, "Time is money." But I think time is ___1___ important than m

[单选题]Someone says, "Time is money." But I think time is ___1___ important than m