Excessive clearances in the main or crank-pin bearings will sometimes be indicated by （） before any bearing knock is heard.

[单选题]（） clearances in the main or crank pin bearings will sometimes be indicated by loss of pressure in the lubricating system before any bearing knock is heard.A . Too largerB . Too smallerC . ExcessD . Excessive

[单选题]To prevent excessive __ in the transverse girders, the tie bolts are positioned as close to the center of the crankshaft as possibleA．thermal stressesB．bending momentsC．thermal loadsD．surface tensions

[单选题]To prevent excessive __ in the transverse girders, the tie bolts are positioned as close to the center of the crankshaft as possibleA．thermal stressesB．bending momentsC．thermal loadsD．surface tensions

[单选题]Excessive vibration of an automatically fired auxiliary boiler can be caused by （）A . air or water in the furnaceB . combustion pulsesC . fuel oil pump failureD . flame failure

[单选题]Excessive alkalinity of the water in an auxiliary boiler can cause （）.A . caustic embrittlement of the boiler metalB . acidic corrosion of the boiler metalC . hard scale deposits on the boiler tubesD . etching of the heat exchange surface

[单选题]LAO45°+CRAN15°表示（）。A . 右前斜45°，头位15°B . 左前斜45°，足位15°C . 左前斜45°，头位15°D . 右前斜15°，头位45°E . 左前斜45°，足位15°

[单选题]LAO45°+CRAN15°表示A.右前斜45°，头位15°B.左前斜45°，足位15°C.左前斜45°，头位15°D.右前斜15°，头位45°E.左

[单选题]E．xcessive oil foaming in the crankcase of a refrigeration compressor is most likely to occur when the compressorA．has run continuously for a long periodB．suction pressure is below normalC．oil level is below normalD．starts after a long idle period

[单选题]In a diesel engine, excessive cylinder liner wear will cause （）(1) increased blow-by(2) wear between the piston ring and grooveA . (1) only is correctB . (2) only is correctC . both (1) and (2) are correctD . neither (1) or (2) axe correct

[单选题]What effect does excessive positive ions have on some people?A．They think they are mad.B．They feel very tired.C．They become violently sick.D．They are too tired to do anything.