A mechanical ventilator is used in times of respiratory failure it helps air flow in and out of the lungs to assist in breathin. It's an important breathing aid in terms of emergency.
Pulmonary ventilation is another name for breathing. It involves air flow into the lungs and out of the lungs.
Fossils can only be formed when mud, silt or tar is in the area to preserve the fossil, If erosion does not occur and allows the fossil to form, and Oxygen and microorganisms cannot decay the bones.
