(a) Evolution of surface mass fraction of hydrogen as a function of the central He mass fraction for single stars. (b) Evolution of the effective temperature as a function of the central He mass fraction for single stars. (c) and (e) Evolution of surface mass fraction of hydrogen as a function of the central He mass fraction for the donor star in binarities. (d) and (f) Evolution of the effective temperature as a function of the central He mass fraction for the donor star in binarities.