Breathing source oxygen elements easy to live human
Medulla oblongata is the part of the brainstem that controls the autonomic functions such as sneezing, coughing, digestion and etc.
Answer: Senescent cells
The Senescence of
the eyes is often demonstrated by the presence of <span>senescence cells. They are forms of cells that are normally capable of
replication within mammalian tissues but permanently non-dividing and
share features with oncogene-induced senescence.
</span>Moreover, the accumulation of senescent cells has been overwhelmingly
studied using fibroblasts and has been proposed to act as an ageing mechanism.
For this item, I would go with letter "D. physical destruction of marine habitats". Many of the modern ways of fishing poses an irreversible destruction to marine habitats. These practices include trawling, lining methods, purse seining, etc.