In human populations, ethnic hatred and civil war can cause two populations to become reproductively isolated as happened in Rwanda where the Tutsi and Huttus blamed each other for the problems of their nation and with the result of no friendly relation between the two and a resulting genocide.
Answer:
D competition for resources
Explanation:
I suppose it is the density, having more pockets of air in between the granules of sawdust. Air has oxygen. What does a fire need to strive? Oxygen.
