Answer:
True 
They all are pruning methods because they are all for pruning grape vines
 
        
             
        
        
        
A biotic factor is all of the students in the classroom.
Hope this helps!!
        
                    
             
        
        
        
Answer:
The coastal upwelling and changes in wind and water circulation patterns is the main natural cause of dead zones.
Fertilizers cause hypoxia due to the over growth of algae on the surface of water bodies.
Explanation:
Coastal upwelling is the cause of dead zones in which water that is present in depth comes to the surface of ocean due to the movement of water because of wind. Fertilizers cause hypoxia due to the over growth of algae on the surface of water bodies. The fertilizers increases the algal growth by providing nutrients necessary for its growth. This over growth decreases oxygen concentration in water and affect marine organisms.
 
        
             
        
        
        
Answer:
Cold Air Will Sink
Explanation:
As hot air rises cold air will sink, cold air is more heaveir than hot air.