Hallo~~
Your question is related to genetics.
Have you ever done a Punnett Square? This question forces you to make one. If your cross a homozygous type A (AA) and homozygous type O (OO) you should get 100% AO. Understanding genetics, an AO gene means a type A blood. Therefore, it's 100% type A blood (AO).
 
        
             
        
        
        
Potable water is water that is safe to drink
        
             
        
        
        
I think its ADP because it breaks off the third phosphate. 
        
                    
             
        
        
        
The environment would probably be a grass land or rich forest
        
             
        
        
        
D. Photosynthesis only takes place in the light, while cellular respiration takes place in the light and dark.