Over population, is the answer
        
                    
             
        
        
        
Answer:
Sample
Explanation:
Samples are used in statistical testing when population sizes are too large for the test to include all possible members or observations. A sample should represent the population as a whole and not reflect any bias toward a specific attribute.
 
        
             
        
        
        
Answer:
Explanation:
Spatial competition occurs when the amount of space available is inadequate to satisfy existing or expected future wants. For example space for transport or agriculture may be at the expense of space for ecosystems
 
        
                    
             
        
        
        
Answer:
Fields should be bigger to feed more people, but they are smaller because people live on those lands.
Explanation:
A higher population density means that there are more people in an area. As there are more people, there is not enough space for all of them to live in the city, so new cities and towns emerge occupying the field's lands used for cattle raising and agriculture. There should be larger fields to feed all the population, but they become smaller because parts of them are now populated.
 
        
             
        
        
        
Answer:
Check Explanation.
Explanation:
In order to be able to answer this question effectively and efficiently we have to consider the Newton's law of Universal gravitation which is given by the mathematical representation below; 
Gravitational force, F = G (m1 × m2) / r^2.
Where G = Gravitational constant, m1 and m2 and the masses of body one and two respectively and r = distance. 
So, we can deduce that the mass(in form of kinetic energy) increase at large distance and this makes the speed to reduce.