Answer:
The force of surface tension in the lungs is so great that without something to reduce the surface tension, the airways would collapse after exhalation, making re-inflation during inhalation much more difficult and less effective. Collapse of the lungs is called alectasis.
Explanation:
 
        
             
        
        
        
The best description about the brain stem is: it is the most important organ of our body's survival. It connects the brain and the spinal cord, controls the vital organs like the lungs and heart and it also coordinates the many essential body reflexes.
        
             
        
        
        
Answer:
is the higher number of a blood pressure reading.
Explanation: systolic blood pressure is the higher number of a blood pressure reading and its measure in millimeter of mercury.
Systolic pressure is the amount of pressure in the arteries when contraction takes place in heart. Diastolic pressure is the pressure the heart when it relaxes. It is the lower number of blood pressure reading 
When the systolic pressure is >120mm Hg and diastolic is less than 80mm Hg it is normal
120-129mm Hg and diastolic less than 80mm Hg it high and such person needs a regular medical check up
But when systolic 129-139 mmHg 
and diastolic is 90mm Hg or above it means the individual is having hypertension stage 1
Above 140mm Hg is hypertension stage 2 and it is the most severe stage. It means the person is hypertensive and medical attention needs to be seek for necessary treatment as this could lead to death of such individual if not well managed.
 
        
             
        
        
        
Answer:
About 100 times more than other planets.
Explanation:
The Sun would be about 100 times bigger than the earth planet in the scaled-down model of the solar system because in the reality the size of sun is 109 times more than the earth so making a model more perfect and nearer to reality we have to maintain the diameter of the sun more than 100 times than the earth and other planets.
 
        
             
        
        
        
The answer is : ingestion and digestion
; propulsion and secretion
; absorption and elimination
Digestive system will receive and digest food to make the molecule smaller. After the molecule become small, it could be absorbed by the body. The waste that couldn't be digested and absorbed will be eliminated as feces. Some of the waste from the body like bilirubin would be dumped through feces too.