A. Hereditary rulers of a country
It's called condensation.
With the invention of the stethoscope, physicians were able to listen to the various sounds made by the heart and lungs. And began to be able to identify if patients had any diseases or ailments.
Before WWII Germany was granted some of their wants, and this was called appeasement. Appeasement was done because the Allies thought that if they gave in to some of their demands, it would keep Germany from doing anything major, such as war. The biggest concession was to allow Germany to take over the Sudetenland, which was in Czechoslovakia but inhabited by native German speakers that wanted to be allied with Hitler.
