单项选择题

Cross scavenging requires the fitting of （） to prevent air or exhaust gas escape when the piston is at the top of the stroke.

A.a exhaust valve
B.a piston skirt
C.a piston crown
D.an air suction valve

相关考题

Crankshafts of medium speed engines are （） from a singl...

单项选择题Crankshafts of medium speed engines are （） from a single piece of steel.

A.unusually solid welded
B.never be solid forged
C.almost invariably solid forged
D.almost invariably be welded

Cracks in the cylinders and cylinder covers may （） uneq...

单项选择题Cracks in the cylinders and cylinder covers may （） unequal heating.

A.result from
B.result in
C.give out
D.given from

Cracks in cylinder and cylinder covers may （） from uneq...

单项选择题Cracks in cylinder and cylinder covers may （） from unequal heating.

A.make
B.cause
C.result
D.produce

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