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</span>Seafloor spreading occurs at mid-ocean ridges, where new oceanic crust is formed through volcanic activity and then gradually moves away from the ridge. Seafloor spreading helps explain continental drift in the theory of plate tectonics.
Earlier theories (e.g., by Alfred Wegener) of continental drift were that continents "plowed" through the sea. The idea that the seafloor itself moves (and carries the continents with it) as it expands from a central axis was proposed by Harry Hess from Princeton University in the 1960s. The theory is well-accepted now, and the phenomenon is known to be caused by convection currents in the plastic, very weak upper mantle, or asthenosphere.
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Natural vegetation refers to a plant group, which has grown naturally without human aid and has been left undisturbed by humans.
Mnemonics are very personal. What works for one person might not work for somebody else. Without knowing you, Here's one that may be so surprising that it might work for a lot of people: ..... "When I was on Brainly one night and asked for the capital of Honduras, Al the Genius said it's Tegucigalpa."