Refreshed shocks: long-lived reverse shock model. Left panel: initial distribution of the Lorentz factor (lower part) and kinetic power (upper part) in the flow as a function of injection time t_inj. Right panel: synthetic light-curves at 2 eV (black, dotted line) and 10 keV (grey, dotted line) together with the data. The kinetic energies in the spike and extended emission components are  erg and . The density of the external medium, redshift and slope p of the electron distribution are the same as in Fig. 1. The adopted microphysics parameters are in the shocked ejecta.