Answer:
B. Catastrophism
Explanation:
Catastrophism is the theory that states that the Earth was mostly shaped by very sudden effects. These sudden and short-lived events would occur worldwide in scope and change the Earth rapidly. This is in contrast to uniformitarianism that states that slow incremental changes made the Earth like it is today. Changes like erosion.
 
        
                    
             
        
        
        
Answer:
Phagocytic defense in the normal lung is shared principally by two kinds of cells - alveolar macrophages that reside on the air surface and roam the alveoli and PMNs that circulate in the intravascular space or are stored transiently in areas adjacent to the capillary-alveolar interface (marginated in capillaries) 
Explanation:
mark brainliest pls
 
        
             
        
        
        
<span>                                                    RNA
ribonucleic acid, a nucleic acid present in all living cells. Its principal role is to act as a messenger carrying instructions from DNA for controlling the synthesis of proteins, although in some viruses RNA rather than DNA carries the genetic information. I hope that this helps you out!!!
                       ~</span><span>razerthebrainieace</span>
        
             
        
        
        
The cell is fundamental unit of structure and function in living organisms .All cells arise from pre-existing cells by division . The cell theory states that the cell is the basic unit of life and that all other cells are developed from an existing cell. This theory was developed way back in the mid of 17th century.