Sperm cells are stored an matured in the Epididymis
        
             
        
        
        
The correct answer that would best complete the given statement above would be CELL RESPIRATION and FOSSIL FUELS. Carbon dioxide enters the atmosphere by animal and human cell respiration and the burning of fossil fuels. Human activities such as BURNING FOSSIL FUELS and RESPIRATION cycle carbon through the carbon cycle. Hope this is the answer that you are looking for.
        
             
        
        
        
Answer:
Resistance = 30 Ω
Explanation:
The resistance of an electric circuit = 
voltage = 24V
current (I) = 0.80A
Therefore, R =  
 
R = 30 ohms
 
        
             
        
        
        
Answer:
Active transport requires energy for the movement of molecules whereas passive transport does not require energy for the movement of molecules.
Explanation:
 
        
             
        
        
        
Answer:
Hair cells are present inside the inner ear that acts as a receptor of sound. Researchers affirmed that once there is a damage to the hair cell, it can regenerate in birds. 
Damage hair cell can lead to loud noise which in turn affect the ear. The supporting cells are present along with the hair cells. When the hair cells get damaged, the supporting hair cell gets the signal to start the process of regeneration.