Answer: to defend itself
Explanation:
This natural reaction prepares you to either flee or protect yourself in dangerous situations. Your heart rate increases, your adrenal gland releases cortisol (a stress hormone), and you receive a boost of adrenaline, which increases energy. This fight-or-flight response occurs in the alarm reaction stage.
 
        
                    
             
        
        
        
Heat stroke is the most serious heat-related illness. It occurs when the body becomes unable to control its temperature: the body's temperature rises rapidly, the sweating mechanism fails, and the body is unable to cool down. Body temperature may rise to 106°F or higher within 10 to 15 minutes.
        
             
        
        
        
Being around people you like and are good for you
        
             
        
        
        
Answer:
After lifting weights for two weeks, Joe finds that the weights he has been lifting do not feel very heavy to him anymore. This is an example of Muscle adaptation principle - D.