Variation on the logarithmic scale of the mass fraction of hydrogen, helium, and CNO elements as a function of the Lagrangian mass coordinate in solar units in the (a) 120 M_⊙ model and (b) the 70 M_⊙ model for the two prescriptions of the mass losses studied in the present work at the end of the main-sequence stage. The meaning of the different line styles is the same as in Fig. 3. Vertical grey lines represent the total mass of both models, which correspond to the final masses at the end of MS tabulated in Table 3.