log ϵ(Th) plotted against neutron capture elements: Eu, La and Nd. A diagonal 1:1 relation (black), the initial ratio (green) (Schatz et al. 2002) and the expected ratio assuming an age of 13 Gyr (red) are plotted for comparision. Error bars are also given in the lower right of each plot. The symbols are as same as in Fig. 3. The two stars that have much higher Th than Eu are HE 0105−6141 and HE 1332−0309.