Consider the model of the oxygen cycle on earth. the majority of earth's oxygen reservoirs are found in the

Atmosphere 
biosphere
hydrosphere
the main oxygen cycle is photosenthisis

The virus is considered to be are living item since they have hereditary material dnas or rnas. they can imitate and change. they respond to boosts, for example, radiation, chemicals, and warmth. they have antigenic properties. they are proficient to duplicate with a same hereditary constituent.