With age, the tissues making up a heart valve can lose flexibilty
        
             
        
        
        
the third potion listed is the correct answer. because in its name it implies that there is more than one lens
 
        
             
        
        
        
capillaries is the answer
 
        
             
        
        
        
Answer:
Explanation:
In the  structure of  Nucleic acids the nucleobases (nucleotide and bases) are arranged is  a specific  form.This form of arrangement is called Base stacking.It simply refers to the bond formed between the adjacent bases.
These nitrogenous bases of (A,T,C.G) pairing  in DNA are in planes in geometry.The bases planes stack  with one another.This form of arrangement  give rooms for more Van der Waals interactions in the plane of the bases.Although the Van der Waals are weak interactions,the bond ensure that these bases are braided or twisted together to give maximum energy,to maintain stability of the bases,and therefore of DNA structure 
Therefore in water  and other aqueous solution the stability of  structure of DNA is enhanced by the base stacking,(coiling or twisting)with maximum van der waals interaction  among the bases, than the hydrogen  bonds formed between bases.Generally there are more stacking among G-C,than A-T,thus the former pairing contribute more the structural stability than the latter (A-T)
 
        
             
        
        
        
Answer:
Your bloodstream.
Explanation:
The cells in your pancreas produce insulin which needs to be sent to the rest of your  body to tell your cells to take in glucose (sugar) for energy. In order to get sent out of  the pancreas' cells, the insulin needs to go through your bloodstream.