Complex sentence: At the bottom of the racial scale of non-Aryans were Jews, Romani, and blacks; the Nazis sought to immediately exterminate Jews and Romani, while blacks were to be segregated and eventually exterminated through sterilization policies.
Split into simpler sentences: At the bottom of the racial scale of non-Aryans were Jews, Romani, and blacks. The Nazis sought to immediately exterminate Jews and Romani, while blacks were to be segregated and eventually exterminated through sterilization policies.