Li-rich (filled triangles) and Li-normal (open triangles) giants with good quality data are superposed with dust shell evolutionary models. Different colors; magenta, green, cyan, and blue represent the loops of the evolution of a dust shell with mass-loss rates, 1 × 10^-10, 1 × 10^-9, 5 × 10^-9, and 3 × 10^-8, respectively. Four varieties of lines in each color indicate the different photospheric temperatures and radius, T_eff = 5000 K, R = 20 R_⊙, T_eff = 4000 K, R = 20 R_⊙, T_eff = 5000 K, R = 10 R_⊙, T_eff = 4000 K, R = 10 R_⊙ of the dust shell hosting stars, radially outward, respectively.