For a polymer that behaves as a viscous liquid at low frequency, label which curve is $G^{\text{'}}$

and which is $G^{\text{'}\text{'}}$ for the rheology data below $($open or closed symbols$).$ What happens

around a frequency of $1rad{s}^{-1}?$ The solid lines are fits to what model? What kind of

material could this be $($cross$-$linked, entangled, unentangled, reversibly cross$-$linked...$)?$