A defective injector nozzle in a propulsion diesel engine can cause（）

A . prolonged maintenance intervals B . improved atomization C . greater fuel economy D . incomplete combustio

A . being compressed B . to be pumped up C . is pressurized D . are built u

A . smoky exhaust B . starting failure C . overload D . over speed

A . camshaft B . main spring C . rack position D . nozzle orifice size

A . higher firing pressure B . more power output C . lower fuel pressure D . less power output

A . erosion and cratering of the nozzle orifices B . fuel leakage into the nozzle drain line C . fuel leakage before and after injection D . insufficient fuel delivery though that nozzle

A . The fuel metering will vary B . The fuel will explode C . The cylinder head will crack D . The engine will sto

A . no fuel will be delivered through the nozzle B . the nozzle will overheat and crack C . time of injection will change D . fuel will leak into the drain line

A . heat conduction into the injected fuel oil B . heat conduction into the water jacket wall C . water circulation through passages in the holder D . fuel oil circulation through passages in the holder

A . in contact with the fill opening to guard against static spark B . from making contact with the fill opening to guard against static spark C . in contact with the fill opening to allow proper venting D . None of the above

A . excessive fuel nozzle holder cooling B . sediment in the fuel supply C . distortion of the fuel spray pattern D . improper atomization of the fuel

A . top and bottom B . to and fro C . up and down D . back and forth

A . high firing pressure B . overload of that particular cylinder C . smoky exhaust D . cooling water temperature rise

A . 间接宾语 B . 宾语补语 C . 直接宾语 D . 主语补语

A . lower compression pressures B . overheating without smoking C . failure to start D . a run away without load

A . low-velocity fog only B . a solid stream only C . a solid stream and foam D . a solid stream and fog

A . smoky exhaust B . starting failure C . ignition relay D . over speed

A . crankshaft B . camshaft C . piston rod D . rack and pinio

A . the firing pressure in the cylinder B . a metering helix inside the pump C . varying the physical length of the plunger stroke D . varying the clearance between the injector cam and the injector rocker arm

A . shield fire fighters from radiant heat B . break up burning material C . get the most water possible on the fire D . drive heat and smoke ahead of the fire fighter

A . smoky exhaust B . starting failure C . overload D . over speed

A . the hose could burst B . the nozzle end will whip about causing damage or injury C . water damage to vessel's cargo or structure D . personnel might trip over the hose

A . piston B . drum C . plunger D . barrel

Scientists have discovered a genetic defect that appears to cause deficit-hyperactivity disorder, more commonly known as hyperactivity. People afflicted with this disorder have trouble focusing their attention and controlling impulses, and tend to be rest-less and aggressive. The defect occurs in a gene that regulates the body's use of the thyroid hormone. This finding was made in continuing study organized by the National Institute of Diabetes and Digestive and Kidney Diseases in which 70 percent of children inheriting the gene were hyperactive while only 20 percent of the children not inheriting the gene were hyperactive. And although the researchers admit that this defective gene probably accounts for only a fraction of cases of hyperactivity, this discovery will allow doctors to spot newborn babies likely to have the disorder, and also to provide clues for its cause and treatment.