Decomposers are necessary to the food chain because they break down the results of the food chain into the basic elements that producers can then use to begin the process over again. Decomposers include groups of bacteria that help to speed up the decaying process of dead plants and animals. 
Hope that helped! =) 
        
                    
             
        
        
        
Answer:
an automatic response established by training to an ordinarily neutral stimulus.
Explanation:
For example, the smell of food is an unconditioned stimulus, a feeling of hunger in response to the smell is an unconditioned response, and the sound of a whistle when you smell the food is the conditioned stimulus. At this point, the response becomes known as the conditioned response.
 
        
             
        
        
        
First its very efficent.it runs really fast and produces twice as mutch pruducts. on the other hand its like a nuclear bomb