Low-resolution lines (HST) from the z_abs = 1.9410 system. The vertical ticks in the H i panels indicate the positions of individual Voigt components. The profiles of metal ions are calculated using the velocity-density distributions restored on the basis of high-resolution lines shown in Fig. 3. The red synthetic profiles in the O iii and O iv panels are calculated for two oxygen abundances [O/C] = 0.2 and 0.3 (see text for details).