  Supernova remnants have long been regarded as sources of the Galactic cosmic
rays up to petaelectronvolts, but convincing evidence is still lacking. In this
work we explore the common origin of the subtle features of the cosmic ray
spectra, such as the knee of cosmic ray spectra and the excesses of
electron/positron fluxes recently observed by ATIC, H.E.S.S., Fermi-LAT and
PAMELA. Numerical calculation shows that those features of cosmic ray spectra
can be well reproduced in a scenario with e$^+$e$^-$ pair production by
interactions between high energy cosmic rays and background photons in an
environment similar to the young supernova remnant. The success of such a
coherent explanation serves in turn as an evidence that at least a portion of
cosmic rays might be accelerated at young supernova remnants.
