It seems oil ________ from this pipe for some time. We’ll have to take the machine apart to put it right.

A．) had leaked          B) is leaking           C) leaked           D) has been leaking

 

[单选题]“Before disconnecting the oil pipe, would you flush the oil retained in the pipe?” asked the oil barge owner （）A . by using of fresh waterB . with compressed airC . by using of sea waterD . with chemical compound

[单选题]The selection of an oil from the （） depends to a great extent on the operating conditions, the design of the engine and the type of fuel to be burned.A . commercially availableB . commerciallyC . commercial availableD . commerce available

[单选题]The removal of （） from lubricating oil will reduce engine wear and possible breakdowns.A . contaminating waterB . contaminated additivesC . contaminated fuelD . contaminating impuritie

[单选题]The lubricating oil is pumped from the drain tank, very often with （） in the suction line.A . a filterB . a strainerC . a magnetic filterD . a fine strainer

[单选题]The oil is drawn from a drain tank through （）, one of a pair of pumps, into one of fine filters.A . a strain tankB . a head tankC . a service tankD . a strainer

[单选题]Fuel oil is pumped by means of （） from the bunker tanks.A . a transfer pumpB . a bilge pumpC . a service pumpD . a vacuum pum

[单选题]Lube oil pumps taking suction from the sump of most small marine engines are usually （）.A . of the diaphragm typeB . of the centrifugal typeC . of the positive displacement typeD . independently driven by electric motor

[单选题]_______can cause oil flow from water outlet of the oil purifier.A．Oil inlet valve opening too quicklyB．Oil temperature little higher than normalC．Diameter of gravity disc too smallD．Viscosity of oil little lower than normal

[单选题]An energy analyst forecasts that the price per barrel of crude oil five yea

[名词解释] 下管pipe sinking