1. Testing only one variable
A controlled variable means its the one that stays the same. In a controlled experiment, it means there is only one manipulated, (changed) variable. 
        
                    
             
        
        
        
Answer:
Mudslide
Explanation:
This is an example of a mudslide. Because it is on a mountain and it is sliding down hill that is why it is called a slide and because it is picking up eroded rocks, mud and grass it is called a mudslide. 
 
        
             
        
        
        
Hi
The answer is : Somatic 
Because somatic relating to the body 
I hope that's help:-
 
        
             
        
        
        
option c is the answer 
Explanation:
septum is present between the two ventricles and separates the oxygenated and deoxygenated blood. hence if it gets ruptured then the two blood will mix up. thanks 
 
        
             
        
        
        
C) Rocks
May I have brainliest??
Hope This Helps!!