Explanation:
option c is correct answer
 
        
             
        
        
        
Answer:Specific proteins are made only at certain times in certain cells.
Explanation:
 
        
             
        
        
        
<h3><u>Answer;</u></h3>
756 mm Hg
<h3><u>Explanation;</u></h3>
- Intrapleural pressure is the pressure of the air within the pleural cavity, between the visceral and parietal pleurae. This pressure changes during different phases of breathing. 
- <em><u>Due to certain characteristics of the lungs, the intrapleural pressure is always lower than, or negative to, the intra-alveolar pressure. It  remains approximately –4 mm Hg throughout the breathing cycle.</u></em>
- <em><u>Therefore; if the intrapulmonary pressure was 760 mm hg then the intrapleural pressure will be (760 -4) mm Hg, that is 756 mm Hg</u></em>
 
        
        
        
The therapy can find the damaged cancer cells and prevent it from reproducing, or even taking it off the gene so that none person from the next generations will suffer the same.
        
                    
             
        
        
        
Answer:
D. The Earth system essentially contains a fixed amount of chemical elements that cycle continuously throughout the system.