The precambrian era makes up about 90% of the earths history, but there was little to no living organisms at the time other than microscopic ones. The first eukaryotes were found in the cambrian period after the precambrian period, not only that but at the end of the precambrian era in the Proterozoic era there was a mass extinction of about 70-80% of all living organisms
        
             
        
        
        
Answer:
cell wall
Explanation:
Cell wall is the outermost boundary in plant cell whereas plasma membrane or cell membrane is the outermost boundary in animal cells. In a plant cell, cell membrane is found in the inner side of the cell wall.
 
        
                    
             
        
        
        
Answer:
its B. <em><u>thoracic</u></em><em><u> </u></em><em><u>cavity</u></em><em><u>.</u></em>
Explanation:
it is the ventral body chamber that contains the pericardial cavity (the heart) and the pleural cavity (the lungs).
 
        
                    
             
        
        
        
Answer:
need more information to answer this question