Local shear failure occurs when the shear stresses parallel to the grain, i.e. shear stresses acting in the longitudinal-tangential (LT) or longitudinal-radial (LR) planes, exceed the shear strength of the beam. The shear strength of a wood member is difficult to quantify.
Probably minerals because they are definitely in soil
It's one of the following:
1) Social Science
2) Sociology
3) Anthropology
I'm leaning towards social science, but there are far too many variables in what constitutes a probable, correct response to this particular question.
Acid - an acid is a chemical species that donates protons for hydrogen ions and or excepts electrons. Most as it’s contain hydrogen atom bonded that can release (dissociate) to yield the cation and anion and water.