Analog requires a lot of bandwidth, but digital requires less.
The ependymal cells line the ventricles of the brain. They compose a thin lining along the brain's ventricle cell, and the central canal of spinal cord. They are a type of glial cells. They play an important role in the production of cerebrospinal fluid.
Answer:
Oxygen (O) , Carbon (C) , Hydrogen (H) , Calcium (Ca) , Iron (Fe) , Sodium (Na) , Iodine (I) , Magnesium (Mg) , Selenium (Se)