Cerebrospinal fluid (CSF), clear, colourless liquid that fills and surrounds the brain and the spinal cord and provides a mechanical barrier against shock. Formed primarily in the ventricles of the brain, the cerebrospinal fluid supports the brain and provides lubrication between surrounding bones and the brain and spinal cord. When an individual suffers a head injury, the fluid acts as a cushion, dulling the force by distributing its impact. The fluid helps to maintain pressure within the cranium at a constant level. 
https://www.britannica.com/science/cerebrospinal-fluid
        
             
        
        
        
B. Testicle, because it secretes hormones
        
                    
             
        
        
        
Answer:
Time-31 minutes. Push- ups, sit-ups, and crunches. Moderate. Cardiovascular and Muscular.
Explanation:
Just put this in what you have to do. Put the date down.  Just put the rest down like time when you started. This activity lasted 31 minutes.
 
        
             
        
        
        
Tall bc I am tall and it’s okay