They were known as muckcrackers during the progressive era
the answer is a microscope .
pls mark brainliest
The Nazis established killing centers for efficient mass murder. Killing centers were almost exclusively “death factories.” They are also referred to as “extermination camps” or “death camps.” Nazi concentration camps, by contrast, served primarily as detention and labor centers. At the killing centers, Nazi officials employed assembly-line methods to murder Jews and other victims. German SS (Schutzstaffel; Protection Squadrons) and police murdered nearly 2,700,000 Jews in the killing centers by asphyxiation with poisonous gas or by shooting.
It was "B. Philippe de Vitry" who was a Medieval composer and was also a politician and author famous for his writings on music theory, since at the time not many people knew the fundamentals of such theory.
