发动机进气提前角一般为（)。

A.40°-70°

B.5°-25°

C.10°-30°

D.45°-80°

A.A+δ;

B.β+γ;

C.A+γ;

D.β+δ

A.进气提前角

B.进气迟后角

C.排气提前角

D.排气迟后角

A.40°~60°

B.10°~30°

C.0°~10°

D.30°~50°

A.40-70

B.5-25

C.10-30

D.45-80

A.10～30°

B.30～50°

C.40～60°

D.20～40°

A.a+180°+b

B.a+180°+y

C.y+180°+p

D.b+180°+p

A.a+180°+b

B.a+180°+y

C.y+180°+p

D.b+180°+p

A.进气提前角+排气迟闭角+排气提前角

B.排气提前角+进气迟闭角+进气提前角

C.进气提前角+进气迟闭角+排气迟闭角

D.排气提前角+排气迟闭角+进气提前角+进气迟闭角