Vee-type engines have the connecting rods from two cylinders connected to each （） of the crankshaft.

A.the inlet valve is open
B.the exhaust valve is open
C.both valves are closed
D.both valves are open

A.is running
B.stops
C.is repaired
D.lacks of oil

A.variable injection timing
B.variable inlet tonnage
C.vertical incoming tonnage
D.vertical inlet tank