The evolutionary track as predicted by models with various metal-enhanced wind efficiencies. The two left panels are log(C/O) vs. 12 + log(O/H) and [O/Fe] vs. [Fe/H]; the two right panels are oxygen abundance vs. gas fraction and Y vs. (O/H). All 5 models have the same burst sequence (t = 1/3/5/7/9/11/13 Gyr, and d = 0.1 Gyr for each burst), but different wind efficiencies. Solid green lines: λ_mw = 0; dash-dotted black lines: λ_mw = 0.2; long-dashed red lines: λ_mw = 1; short-dashed blue lines: λ_mw = 3; dotted magenta lines: λ_mw = 10. All these models assume the same total infall mass M_inf = 10⁹ M_⊙. The observational data are the same as in Figs. 2–4, BCDs, dIrrs, and DLAs are plotted in open cyan circles, open cyan triangles, and open green squares here.