Answer:
animal wastes and fertilizers
Explanation:
The majority of the nitrates that are polluting the rivers come from the animal wastes and from the fertilizers used in the agriculture. The increased amounts of nitrates in the rivers causes eutrophication. This basically means that the water is becoming over-saturated with nutrients. This leads to the spreading out of the algae. As the algae spread out more and more, they cover the surface part of the water, so large portions of the rivers do not receive sunlight, which kills of the organisms that use photosynthesis. Further, the algae reduce the amount of oxygen in the water, often resulting in dying out of the fishes. It is a chain reaction that leads from one thing to another and the end result is devastating.
I’d say C.
A doesn’t make sense, they definitely could’ve domesticated animals in that time.
B doesn’t make sense either, they could’ve easily seen smoke signals, the sky wasn’t filled with them often.
C is just a weird answer. I doubt they were “passive observers” but probably the best answer to the question.
D doesn’t add up because they definitely needed agriculture/food surpluses. They were always hunting, they obviously ran out of food rather quickly.
So C is the answer.
Answer:
the fourth one
Explanation:
its the most reasonable one, without the predators hunting the number of preys would overpopulate, sorry if im too late
It was Carl O. Sauer who did
Answer:
There are 54 countries in Africa, today.
Explanation:
