Answer:
The Rosetta Stone
Explanation:
You might have heard of this stone before. It is a popular language learning app but it also is an ancient stone that helped people to decipher ancient Egyptian hieroglyphics. It has a message in hieroglyphics and demotic script with a Greek translation on the bottom, so people were able to figure out what many of the hieroglyphs meant.
Have a wonderful day! :D
Answer:
The spectral types and sub-classes represent a temperature sequence, from hotter (O stars) to cooler (M stars), and from hotter (subclass 0) to cooler (subclass 9). The temperature defines the star's "color" and surface brightness. ... Stars are also classified by luminosity class.
Explanation:
It's becasue human populations are concentrated in areas that are lacking proper resources.
Their progress and wealth is highly dependent on the harvests, and the price of grain. They probably have to import some industrial products and if they had a bad year (weather, other catastrophies, poor technology) they can't get the necessary amount of industrial products in exchange for their surplus e. g. in grain. There are so many standards and requirements about the quality of food production that no country can survive solely on agriculture without high quality technology (machines, unharmful fertilizers, research-based breeding, etc.).
