Which of the following conditions could cause the feed pump for an auxiliary boiler to lose suction?（）

[单选题]Which of the following conditions could contribute to the cracking of a diesel engine cylinder head?A．Leaking seal ringB．Insufficient heat transfer from the exhaust valvesC．Blocked cooling water passages to the headD．Excessive scavenging air provided

[单选题]Which of the following conditions will make a relation that is in first normal form. to be in second normal form?Ⅰ.every non-key attribute is functionally dependent on the full set of primary key attributes.Ⅱ.no non-key attributes exist in the relati

[单选题]Which of the following conditions is realized by the turbo-charging of a previously naturally aspirated diesel engine?A．Ignition lag increases.B．Lube oil system pressure increases.C．Brake specific fuel consumption increases.D．Mechanical efficiency in

[单选题]Which of the following conditions is true concerning a flammable liquid with a concentration above the upper explosive limit?A．The mixture is too lean to burnB．The mixture is too rich to burnC．The vapor is about to explodeD．Conditions are perfect for

[单选题]Which of the following conditions may contribute to the formation of deposits on the blades of the turbocharger turbine?（）A . Poor combustionB . High cylinder oil consumptionC . Leaking exhaust valvesD . All of the above

[单选题]Which of the following conditions may need to be reduced when operating a large, low speed, main propulsion, diesel engine at low loads?（）A . Injection pressuresB . Control air supply pressureC . Cooling water flow through after-coolersD . Lube oil t

[单选题]Which of the following conditions can cause above normal air temperature to develop in the intake manifold of a four-stroke/cycle turbo-charged diesel engine?（）A . Clogged air intake faltersB . Piston blow-byC . A defective after-coolerD . Faulty exh

[单选题]Which of the following could serve as an appropriate title for the passage ?A．The Theory of Division of LaborB．Adam Smith as the Discoverer of Division of LaborC．Adam Smith, the English EconomistD．Division of Labor, an Efficient Way of Organizing Wor

[单选题]Which of the following problems could cause the high pressure cutout switch to shut down the compressor in a refrigeration system?A．A shortage of liquid refrigerant.B．Excessive frost on the evaporator.C．Excessive condenser cooling water.D．Insufficien

[单选题]5 Which of the following factors could cause a company’s gross profit percentage on sales to fall below the expectedlevel?1 Understatement of closing inventories.2 The incorrect inclusion in purchases of invoices relating to goods supplied in the fol