Answer: The activation energy is: the energy needed to get a reaction started 
Explanation: this is dealing with enzymes and their reactions 
 
        
                    
             
        
        
        
The defining characteristic of the intertidal zone is that it is submerged with water during high tide and exposed to the air during low tide. The zone can take many forms, from sandy beaches to rocky cliffs. It is common for the intertidal zone to change frequently, since it is constantly battered by crashing waves. 
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Answer:
An artificial heart is a prosthetic device that is implanted into the body to replace the original biological heart. It is distinct from a cardiac pump, which is an external device used to provide the functions of both the heart and the lungs. Thus, the cardiac pump need not be connected to both blood circuits.
Explanation: