An astrolabe is a primitive angle-measuring tool. It can be used to - very in-exactly! - measure the altitude above the horizon of a celestial body like the Sun, Moon or Polaris in order to calculate your position.
Medieval gunners used the astrolabe to calculate the height of towers and buildings, in order to more accurately aim their cannons.
I'm pretty sure it is "living under harsh conditions" I could be wrong though.
Your shoe store. You sell the exact same pair of boots but you sell them for a cheaper price. Most likely a customer would eat up a deal like that.
Margarine and butter are examples of substitutes.
Blacks were not really involved in the holocaust as the Jews were. Nazis didn’t persecute black people, but they still saw them as inferior.
