Answer 1

Layers of soil 

O – Horizon or humus	This layer is dominated by organic material (leaves, needles, twigs, moss, and lichens)
A – Horizon or Top soil	It is a part of top soil composed of organic matter mixed with mineral matter.
E – Horizon or Elevated layer	E – stands for elevated layer. This layer is significantly leached of clay, iron, and aluminum oxides, which leaves a concentration of ore.
B – Horizontal or sub-soil	This layer reflects the chemical or physical alternation or parent material. Thus iron, clay, aluminium, and organic compounds are found accumulated in the Horizon.
C – Horizon or Parent Rock	Partially weathered parent material accumulates in this layer.
R – Horizon or Parent Rock	This layer consists of unweathered part of bed rock.