1. [单选题]气缸进气阀开启瞬时的曲轴位置与上止点之间的曲轴夹角称为()
A. 进气提前角
B. 进气定时角
C. 进气延时角
D. 进气持续角
2. [单选题](piston area)×(piston stroke)×(numbers of the cylinders)=engine( ).
A. brake horsepower
B. displacement
C. cylinder volume
D. cylinder clearance
