A.ωn/(S2+2ξωnS+1)(0<ξ<1); B.ωn/(S2+2ξωnS+1)(ξ=1); C.T2/(T2S2+2ξTS+1)(0<ξ<1); D.1/[S(TS+1)]
A.ζ=0 B.ζ>1 C.ζ=1 D.0<ζ<1
A.變好 B.變壞 C.不變 D.不一定