When starting an engine, the compressed air enters the cylinder when the corresponding piston is in position of its（）

单项选择题The starting air entering the cylinder begins when the piston（）

A.has nearly come to the TDC
B.has just past the TDC
C.has nearly come to the BDC
D.has just past the BDC

单项选择题In the starting system, the automatic valve is controlled by（）, and the cylinder start valves are controlled by（）

A.pilot air；pilot air
B.handle；solenoid
C.handle；pilot air coming through the distributor
D.solenoid；pilot air coming through the distributor

单项选择题A marine diesel engine is started by（）

A.supplying high pressure oil into a hydraulic motor
B.supplying high temperature air into the cylinder
C.supplying high pressure air into the cylinder
D.electrical igniting

单项选择题In modern installations, the main engine and the standby auxiliary engines（）

A.can be started at low temperature and are free from preheating
B.usually are preheated by steam before being started
C.are kept at a constant temperature and free from preheating
D.are kept at a low temperature to save energy

单项选择题In order to maintain a constant outlet water temperature of 80-85℃ from the engine, a three-way valve is installed（）

A.at the jacket cooler outlet to control the flux through the engine
B.at the jacket cooler outlet to control the flux through the cooler
C.at the engine outlet to control the flux through the engine
D.at the engine inlet to control the flux through the engine