All you have to do is keep track of what letter matches which letter in each column. For example
(DNA strand B) A= (DNA strand A) T
You have the matching letters for each. Do you understand? If not I can help clarify. :3
        
                    
             
        
        
        
Answer:
1.) Why does menstruation begin?
A.) Period happens because of changes in hormones in the body. 
2.) How long does the menstrual cycle usually last?
A.) the menstrual cycle lasts 21 to 35 days while bleeding between 2 to 7 days
<u>-TheUnknownScientist</u>
 
        
             
        
        
        
 kinetic energy and potential energy i believe
Have a good day :)
        
             
        
        
        
Answer:
The ratios of thymine and adenine were similar, as were the ratios of guanine and cytosine. 
Explanation:
deoxyribose + phosphate group + thymine
 
        
             
        
        
        
Answer:
Engineers, as practitioners of engineering, are professionals who invent, design, analyze, build and test machines, complex systems, structures, gadgets and materials to fulfill functional objectives and requirements while considering the limitations imposed by practicality, regulation, safety and cost.
Or,
the person who design and builds or maintain machines or structure..