"The red blood cell<span> survives on average only 120 days. </span>Red cells<span> contain a special protein called hemoglobin, which helps carry oxygen from the lungs to the rest of the </span>body<span> and then returns carbon dioxide from the </span>body<span> to the lungs so it can be exhaled." - hematology.org</span>
        
             
        
        
        
You already answered the question in the picture above
        
                    
             
        
        
        
I think it the answer could be a "steamy mixture of carbon dioxide and water vapor".  
        
             
        
        
        
<em>sieve tube elements are the cells of phloem which allow transportation of photosynthates through phloem...
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how sieve tube elements form sieve tubes:
</u>sieve tube elements are connected end to end and form a long chain which is called sieve tube,,,,
sieve tube elements are connected with the help of a side chain with the help of peptide bond...also one element has tapering end which easily overlaps with other end of next element to form sieve tube,,,,</em>