Answer:
The answer is C)
Explanation:
The predators were unable to keep the population of the mussels down. The mussels took more area of the rock. Other species that needed space did not return to the tidal pool. Otters can also be keystone species as they eat urchins. By doing so, they prevent the sea urchins form eating all the kelp plants and removing the entire habitat for many other species. The Keystone Species theory shows that this impact of few predators, that made up a minor amount of the total species, could have such a high impact on the ecosystem.
The African countries can easily be described and generalized, in the sense of the whole continent, as the economies are predominantly dependent on one or two products.
That dependence on one or two products is making very big problems, and it is also a very big mistake of the governments. When there's a slight variation in the prices on the certain product, the economies are heavily influenced, often in a bed manner.
It is weird though that the African countries have orientated their economies in this way, especially because the continent is very rich in lots of natural resources.
Switzerland, Austria and France,Germany
The Volga river is the largest river in Europe, so that should be the answer.
Answer:
The Great Lakes and Corn Belt occupies a significant portion of this subregion located between the Appalachian Mountains to the east and the Rocky Mountains to the west named A. America’ s central lowlands.
