单项选择题
A.after TDC B.before TDC C.after BDC D.before BDC
In an oil cooler circulated by sea water, the oil is at...
单项选择题In an oil cooler circulated by sea water, the oil is at a larger pressure, the result being that any leak in the cooler will mean a loss of （）.
A.oil B.sea water C.refrigerant D.fresh water
In a four-stroke engine the camshaft rotates at （）.A.ha...
单项选择题In a four-stroke engine the camshaft rotates at （）.
A.half the engine speed B.twice the engine speed C.the engine speed D.four times the engine speed
In an engine with air inlet valve and exhaust valve on ...
单项选择题In an engine with air inlet valve and exhaust valve on its cylinder heads the fresh air will enter into the cylinder （） and the gases exhaust （）, there being an adequate overlap between the inlet opening and the exhaust closing.
A.downwards；upwards B.upwards；downwards C.downwards；downwards D.upwards；upwards
