升降弓时间是通过调整实现的（）

A.进气、做功、排气、压缩

B.排气、压缩、做功、进气

C.进气、压缩、做功、排气

D.排气、进气、做功、压缩

A.阀片、弹簧

B.阀座

C.缓冲片

A.压缩-进气-作功-排气

B.进气-作功-压缩-排气

C.进气-压缩-作功-排气

D.排气-压缩-作功-进气

A.压缩-做功-排气-进气

B.做功-进气-压缩-排气

C.进气-压缩-做功-排气

D.排气-进气-做功-压缩

A.进气30°，排气30°

B.进气45°，排气45°

C.进气60°，排气45°

D.进气30°，排气45°

A.旋转阀进气和簧片阀进气

B.活塞环进气、旋转阀进气和簧片阀进气

C.活塞阀进气、旋转阀进气和簧片阀进气

D.活塞阀进气和簧片阀进气

A.进气0.22-0.28mm排气0.22-0.28mm

B.进气0.25-0.30mm排气0.22-0.28mm

C.进气0.22-0.28mm排气0.27-0.33mm

D.进气0.22-0.28mm排气0.25-0.30mm

A.进气0.28mm，排气0.58mm

B.进气0.36mm，排气0.69mm

C.进气0.25～0.30mm，排气0.30～0.35mm

D.进气0.30～0.35mm，排气0.35～0.40mm