Answer:
Sheep carrying out respiration
Explanation:
Because the sheep is exhaling carbon dioxide into the air
 
        
                    
             
        
        
        
Activation energy is required to start a chemical reaction. Activation energy is the energy needed to allow the reactant to react. Activation energy is measured in Joules (J).
        
             
        
        
        
Answer:
One of these is natural selection, which is a process that increases the frequency of advantageous gene variants, called alleles, in a population. Natural selection can result in organisms that are more likely to survive and reproduce and may eventually lead to speciation.
Explanation:
 
        
                    
             
        
        
        
It allows scientists to explore new explanations for observations.
        
                    
             
        
        
        
iconic bond -> sharing of many electrons 
metallic bond -> sharing of electrons 
covalent -> transferring of electrons 
hope this helps...