Hoyts theory of urban land use and development emerged in response to changes in TRANSPORTATION
Lava cools more rapidly above ground than it does underground because it's much colder above ground than it is underground, speeding up the process.
Think about it this way: If you put a cup of water in two freezers, and Freezer A had a lower temperature than Freezer B, the water in Freezer A would freeze quicker because it is in a colder environment. Hope this helps!
The African countries can easily be described and generalized, in the sense of the whole continent, as the economies are predominantly dependent on one or two products.
That dependence on one or two products is making very big problems, and it is also a very big mistake of the governments. When there's a slight variation in the prices on the certain product, the economies are heavily influenced, often in a bed manner.
It is weird though that the African countries have orientated their economies in this way, especially because the continent is very rich in lots of natural resources.
In recent years, Russia has advanced its military capabilities in the Arctic, reopening old military bases that had been abandoned following the collapse of the Soviet Union in 1991, and bolstering the Russian Navy's prestigious Northern Fleet that oversees operations and defense in the region.
