The default value at which a refresh interval (an interval a sec. server check for zone updates) is 15 minutes. 
If this value is increased, the network traffic is reduced. In the eventuality that the refresh interval expires, the secondary zone will contact the primary zone and request it to initiate the zone transfer.
        
             
        
        
        
The second last one is the answer i think
        
                    
             
        
        
        
It might be an 81 because if you fail 0/100 yo grade is going DOWN
        
                    
             
        
        
        
Answer:
i dont know.prob guess a short loop.
Explanation: