The Sun is a major source of energy for most ecosystems and organisms.
        
                    
             
        
        
        
Once the rock has been weakened and broken up by weathering it is ready for erosion. Erosion happens when rocks and sediments are picked up and moved to another place by ice, water, wind or gravity. Mechanical weathering physically breaks up rock. One example is called frost action or frost shattering.
        
                    
             
        
        
        
D. They both help organisms to move.
 
        
             
        
        
        
Answer:
The invention of the marine chronometer by John Harrison in the middle of the 18th century made true ocean navigation possible. (1) Marine Chronometer In the early 18 th century, knowing your whereabouts on the face of the globe was difficult. As the world’s greatest global power, Britain was extremely keen to remedy that.
 
        
                    
             
        
        
        
Answer:
Reactivity.
Explanation: 
I’m sorry, I don’t really know how to explain this. I just have it memorized. Sorry I couldn’t help more, best of luck!