Answer:
C.) a possible explanation or answer to a scientific question that is based on prior knowledge or research and is testable
 
        
                    
             
        
        
        
The answer would be sewage treatment plants
        
                    
             
        
        
        
Im pretty sure its chemical energy because there also non renewable
        
                    
             
        
        
        
An exosystem is a system or environment that surrounds a child and has a high influence on the child's development; however, the child is not directly involved with with the environment. In order to examine exosystems more closely, one may visit places such as medical centers or religious institutions because both of these affect the development of a child's thinking process.
        
             
        
        
        
Comparative and experimental investigations are two of three scientific investigations, the other is descriptive investigations.
                                        --hope this helps--