Select the organic components of soil.

algae
arthropods
bacteria
clay
humus
nematodes
nitrogen
parent rock
silica
silt

most community's take hundreds of years to become stable

when you breathe in, or inhale, your diaphragm contracts (tightens) and moves downward. this increases the space in your chest cavity, into which your lungs expand. the intercostal muscles between your ribs also enlarge the chest cavity. they contract to pull your rib cage both upward and outward when you inhale.

i think the answer is composed of atoms