Amechanical ventilator may aid directly in pulmonary ventilation. external respiration. internal respiration. pulmonary ventilation and external respiration are correct. pulmonary ventilation, external respiration, and internal respiration are correct.

a. pulmonary ventilation

Explanation:

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.

answer: - few nutrients

high pressure

low temperatures

explanation: 1. few nutrients:   open-ocean zone is located way far from the land, which is the main source of the essential nutrients.2. high pressure: pressure increases by 1 atmosphere for every 10 meters increase in depth.3. ample sunlight: a large fraction of the sunlight is reflected back to the atmosphere from the sea surface. 4. varying salinity: below the thermocline, the water is isolated from the atmosphere so the salinity remains stable over the year.5. low temperatures:   the temperature of open-ocean zone ranges from a low of -2°c to an average of 17°c

they fuse to form they have half as many chromosomes as a somatic cell of the same individual. b