Answer:
alveoli
Explanation:
They are the smallest structures in our lungs where capillaries exchange O2 and CO2 in blood.
 
        
             
        
        
        
As per I know there is no scenario which describes fungi as a decomposer.
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Algae are not plants, animals or fungi. They belong to Kingdom Protista, a diverse group of single-celled eukaryotes. 
Protists have their own kingdom because many species share some characteristics of plants, animals or fungi. 
Algae belong to the group of plant-like protists. 
They are autotrophs that fulfill the role of producer in ecosystems because they make their own food via photosynthesis, like plants.
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Seeing as Peter is male, he's seeing a counselor (which indicates mental/emotional/psychological issues) and has been referred to a urologist, I'd say his problem is erectile dysfunction, or choice #2.
        
             
        
        
        
RNA has great capability as a genetic molecule; it once had to carry on hereditary processes on its own. It now seems certain that RNA was the first molecule of heredity, so it evolved all the essential methods for storing and expressing genetic information before DNA came onto the scene.
        
                    
             
        
        
        
The answer is B
C pairs with G, T pairs with A but in RNA T is replaced with U so A pairs with U