When the walls of the excavations are to be kept vertical and in order to protect the safety of. workmen, the general public, this or other work or structures, or excavation walls, or pipe. installation including ma terials encountered in the excavation which have a tendency to slough.
Hierarchy of Living Things. Biological organization, or the hierarchy of life, is the hierarchy of complex biological structures and system that define life using a reductionistic approach. The traditional hierarchy, as detailed below, extends from atoms (or lower) to biospheres.
A hierarchy (from the Greek á¼±ÎµÏÎ±ÏÏÎ¯Î± hierarchia, rule of a high priest, from á¼±ÎµÏÎ¬ÏÏÎ·Ï hierarkhes, leader of sacred rites) is an arrangement of items (objects, names, values, categories, etc.) in which the items are represented as being above, below, or at the same level as one another. subsumptive containment hierarchy is a classification of objects from the general to the specific. Other names for this type of hierarchy are taxonomic hierarchy and  IS-A hierarchy. The last term describes the relationship between each levelâa lower-level object is a member of the higher class.