Answer:
D
Explanation:
Biotic factors-all the influences that organisms in the community have on each other
 
        
             
        
        
        
The type of weathering is mechanical and the process is abrasion
        
             
        
        
        
Answer:
the right atrium.
Explanation:
Blood enters the heart through two large veins, the inferior and superior vena cava, emptying oxygen-poor blood from the body into the right atrium.
 
        
             
        
        
        
Answer: Most viruses can use host machinery to produce more of themselves
Explanation:
Since viruses carry out no metabolism themselves, they rely solely on the living cells of the host (organism they infect) to replicate and spread from cell to cell.
Thus, viruses do not kill the cells they infect since they need them, and use them to replicate more offsprings
 
        
             
        
        
        
Passive is when materials travel or move across some cell membranes that doesn't use cell energy. 
Active is the meaning of a movement that crosses across some cell membranes that requires the use of cell energy.
Answer: The answer is that passive doesn't use cell energy but active uses cell energy.
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