C is the answer. Particles erode from the main rock to form smaller rocks, and rock particles. It's the only answer that makes sense.
        
                    
             
        
        
        
Answer: Because some products in the market have prices depending on their weight and size, and we need to monitor that carefully to make sure it is the right amount. 
Hope this helps!
        
             
        
        
        
Answer:
A dichotomous key is an important scientific tool, used to identify different organisms, based the organism’s observable traits. Dichotomous keys consist of a series of statements with two choices in each step that will lead users to the correct identification.
Explanation:
Your welcome! :)
 
        
             
        
        
        
Answer:
All organisms that have life, both plants and animals.
Explanation:
You didn't provide an illustration, but I guess I can still help. Biotic factor means that it has life, abiotic means it's not alive (hence the a- at the beginning.) Some biotic factors of a pond ecosystem include: earthworms, fishes, frogs, plants and insects.