Answer: D. The succession of community is completed.
Explanation:
A succession can be define as a series of gradual changes that occur in the biotic community of the ecosystem with respect to the changes that occur in the abiotic or non-living factors with respect to time until the ecosystem attains stability. 
A climax community is the community that develops in the end of the ecological succession. It is the stable community which does not require any further change to occur. With the development of the climax community the succession completes. 
 
        
                    
             
        
        
        
B. The first generation of pea plants were mostly tall.
        
             
        
        
        
Answer:
List three ways of reducing friction. 1.Polishing the rough surface. 2.Providing all bearings or wheels between the moving parts of a machine or vehicles reduce friction and 3.allow smooth movement as rolling friction is less than sliding friction.