The evolutionary track of abundance ratios as predicted by our DLA models. All of these models assume the same SFHs as model M9b3 except for a shorter duration for the first burst used. The red dotted, short-dash, long-dash and solid lines are for models DLA1 to DLA4 whose durations of the first burst are d = 0.01,0.02,0.05,0.1 Gyr, respectively. As a comparison, we also show the best model M9b2 of dwarf galaxy in dash-dotted black lines. All these models assume the same total infall mass M_inf = 10⁹ M_⊙. Open cyan circles are BCDs and open green squares are DLAs, as in Fig. 3.