A hypothesis is a suggested explanation for an observable problem OR a reasoned prediction of a possible causal correlation among multiple problems. A theory is a tested and well substantiated and unifying explanation for a set of verified and proven factors.
        
             
        
        
        
Answer:
The major organs of the nervous system are the brain, spinal cord, sensory organs, and all of the nerves that connect these organs together.
The nervous system reacts to the presence of danger(instinct), stores memories, control the 5 senses, and commands the rest of the organ systems to maintain homeostasis. 
The nervous system works together with the respiratory system, the circulatory system, the muscular system, and many more.
 
        
             
        
        
        
Answer: option C) cowpox and smallpox are caused by the same virus
Explanation:
Cowpox is a skin disease that affects cattle. It is caused by an Orthopoxvirus, with lesions occurring principally on the udder and teats of the animals. 
Human infection may occur from touching infected cows, and thus giving immunity to smallpox (an acute infection caused by the same poxyvirus, in HUMANS) 
So, Jenner's successful use was because cowpox and smallpox are caused by the same virus
 
        
             
        
        
        
Living things obtain and use energy so alive?