Depending on the time, it could be the Phoenicians ( I think this is the best answer; this is what they're known for best) or later in time, the Romans (but they had colonies also elsewhere).
The toothbrush evolved over time and mainly out of necessity. Traces of the first toothbrush can be dated back as early as 3500 B.C.E. These bamboo sticks were then used just like a modern manual toothbrush to clean the teeth. Eventually, the Chinese version of the toothbrush made its way to Europe.
<span><span><span>The crust: low density silicate rock, 5-70 km thick. There are two distinct types of crust.<span><span>Continental crust is variable in thickness and composition. Thickness ranges from 5-70 km. The composition ranges from mafic to felsic.</span><span>Oceanic crust is uniform in thickness and composition. It is 5-6 km thick and is mafic in composition.</span><span>The differences in thickness and density between continental and oceanic are responsible for the existence of ocean basins due to isostatic balance as the crust floats on the more dense mantle.</span></span></span><span>The mantle: high density, ultramafic silicate rock which can flow when subjected to long duration stresses. The mantle is over 2900 km thick and makes up over 80% of the volume of the Earth. The mantle is not molten!</span></span><span>The core: iron and nickel, liquid outer region with a solid center. The core is just over half the diameter of the Earth.</span></span>
probably stamps cuz ya know they're real tiny and they probably thought that in like 30 years no one would be sending a letter so they're like 'yea ok they're just sticky pieces of paper no one cares'