A "micrometer" is the best unit of measurement for measuring the size of an atom. 
        
             
        
        
        
Answer:
The process of making food by the green plant by using sunlight,water,mineral, carbon dioxide,etc.is called photosynthesis.
hope this not childish.
 
        
                    
             
        
        
        
Answer:
B
Explanation:
Birds and flowers have different arrangements of the bases.
Nucleotides are termed as organic molecules which serve as monomer units. Their work is to form nucleic acid polymers, for example, ribonucleic acid and deoxyribonucleic acid. 
They serve as biomolecules in the life-forms on earth. Nucleotides work as building blocks of nucleic acid. They are composed of the phosphate group, five-carbon sugar, and nitrogenous base.
 
        
             
        
        
        
Polymers are many moments strung together. They are linked together by dehydration reactions. (Remove water)