Answer:
<h2>lungs</h2>
Explanation:
An erythrocytes carries oxygen on the lungs.
hope it is helpful to you ☺️
 
        
             
        
        
        
All of the above points are valid for fossils' contributions in understanding the process of evolution. They allow us to study the ancestry, we can see the homologous organs or structures, if fossils are well-preserved; different fossils can lead us to follow the cycles of the changes that occurred during macroevolutions, and fossils can be used to study different populations which had different body structures for surviving in different environmental conditions. 
        
                    
             
        
        
        
Deltas and sand dunes form from erosion
 
<span>a river carrying dirt into a lake is a example of water erosion
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fossils can tell us about environments
when the oceanic and continental plate collide, the oceanic plate sinks below the continental plate
a footprint is a trace fossil 
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An exothermic chemical reaction is  change in the chemicals that can never be undone, an exothermic solution is a combination of chemicals 
        
             
        
        
        
A donor offspring is the donation of sperm