Final answer:
The Nazis immediately subjected the Jews to persecution and extermination upon entering the 'killing centers'. Various methods, including asphyxiation with poison gas and shooting, were employed. Nearly 2.7 million Jews were killed in the killing centers as part of the Nazis' 'Final Solution'.
Step-by-step explanation:
The Nazis immediately subjected the Jews entering the 'killing centers' to various forms of persecution and extermination. Upon arrival at the extermination camps, the Jews were usually separated by gender and age. Those deemed fit for labor were temporarily spared, while the elderly, infirm, and children were often sent directly to the gas chambers.
The Nazis employed different methods of mass murder, including asphyxiation with poison gas and shooting. At some killing centers, such as Auschwitz-Birkenau, the Jews were subjected to selection processes, where SS doctors determined their fate based on their physical condition.
It is estimated that nearly 2.7 million Jews were killed in the killing centers during the Holocaust, as part of the Nazis' 'Final Solution' to exterminate the Jewish population.