Here is the question bro

a)what is humus?

ans-the dead and decayed parts of plants and animals are called humus..

b)explain about plate tectonic theory.

ans- The theory of plate tectonics states that the Earth's solid outer crust, the lithosphere, is separated into plates that move over the asthenosphere, the molten upper portion of the mantle. Oceanic and continental plates come together, spread apart, and interact at boundaries all over the planet.