Final answer:
Elie and other prisoners are advised to appear strong and healthy to avoid being selected for the gas chambers during the second selection in the Holocaust.
Step-by-step explanation:
During the second selection in the Holocaust, Elie and the other prisoners receive advice to appear strong and healthy in order to avoid being selected for the gas chambers. They are told to run when called upon and to maintain good posture and a serious expression. The goal is to convince the Nazi officers that they are fit for labor and not in danger of dying soon.
For example, Elie and his father lie about their ages in order to make themselves appear younger and more able to work. They also try to avoid looking weak or sickly, as the officers are more likely to select those who appear frail.
This advice is given in an effort to survive the selection process and continue living in the camp.