Structure of a star with a mass of 16 M_⊙ before the common envelope stage. Distributions of the hydrogen content by mass X (top line), angular velocity of rotation Ω (second line), amplitude of the meridional circulation velocity U (third line), angular momentum flux F (bottom line): turbulent (solid line), advective (dashed line), and full (thick solid line) are shown depending on the mass of the matter inside the isobar (left panel) and the average distance to the isobar (right panel).