After deportation trains arrived at the killing centers, guards ordered the deportees to get out and form a line. The victims then went through a selection process. Men were separated from women and children. A Nazi, usually an SS physician, looked quickly at each person to decide if he or she was healthy and strong enough for forced labor. This SS officer then pointed to the left or the right; victims did not know that individuals were being selected to live or die. Babies and young children, pregnant women, the elderly, the handicapped, and the sick had little chance of surviving this first selection.
The main reason why this occurred was because the prisoners that were held in the concentration camps were taken there in order to be used as forced labor. The prisoners here were treated badly, ate little, were constantly abused, and worked long hours. Therefore, the Nazi knew that pregnant women, weak individuals, the sick and the old were not going to be able to tolerate this treatment and work efficiently.
The Qin dynasty was the first dynasty to start connecting the various walls into a greater whole. That happened around 221 to 206 BC and was done under the reign of Qin Shi Huang. Though the wall was later improved still by other dynasties, it was during the Qin dynasty that the Great Wall of China was first formed into a cohesive structure.
