The evolutionary track as predicted by models with normal wind. The left two panels are log(C/O) vs. 12 + log(O/H) and [O/Fe] vs. [Fe/H]; the right two panels are oxygen abundance vs. gas fraction and Y vs. (O/H). All the 5 models have the same bursts sequence (τ = 1 Gyr, t = 1/3/5/7/9/11/13 Gyr, and d = 0.1 Gyr for each burst), but different wind efficiencies, solid green lines for λ_m = 0, dash-dotted black lines for λ_m = 0.2, long-dashed red lines for λ_m = 0.5, and short-dashed blue lines for λ_m = 1. A model with long infall timescale (τ = 10 Gyr, λ_m = 1) is shown in magenta dotted line. 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.