appear; disappear
im not 100% sure if thats what is being asked, but they fit and are true
 
        
             
        
        
        
Answer:
Option C, Each subpopulation is linked to all other subpopulations by dispersal.
Explanation:
Each sub-population with in a metapopulation is not only connected by the dispersal distance travelled by an organism but also by the distance between the patches on which two sub population live. There are several other factors that limitise the concept of connection of subpopulation by dispersal factor and these vulnerable factors are – properties of terrain between the patches and its adverse affect on the dispersal behaviour of dispersing agent/species.
Hence, option C is correct.
 
        
             
        
        
        
Answer:
The question is somehow not correct, it suppose to be what is the MASS of an object that needs a force 4500N to accelerate it at a rate of 5 m/s as gotten from another website.
The correct answer is 900kg.
Explanation:
To get the mass of the object use the formula
F=Ma
Where F is force
M is mass
a is acceleration.
F= 4500, M=? a=5m/s
4500= M× 5
M=4500/5
M=900kg
Mass is in kg
 
        
             
        
        
        
C. theory is the answer to your question