A.1~3mm
B.2~4mm
C.3~5mm
D.4~6mm
E.以上都不是
[单选题]A.B.C.D.
[单选题]A.过阻尼B.欠阻尼C.临界阻尼D.无阻尼
[单选题]A.πB.π/2C.π/3D.π/4
[单选题]A.spB.C.D.