Answer:
If the duration of life on Earth was on a scale of 20,000 days, the human species would be present in the Earth for approximately 9 days.
Explanation:
We can't be sure about the exactly age of the Earth, but we can base our calculus in a number between 4400 and 4600 million years, because the most accepted researches shows numbers in this span of time. We can take the average of those limits: 4500 million years.
On another hand the presence in the Earth of human species has not a precise date because of the it does not have a precise date for two main reasons, the scientific evidence does not include all the human species that existed on Earth but it is a very incomplete evidence and besides being an evolutionary phenomenon it is not easy to determine from what moment We can consider that a species belongs to the human race or not. In any case, we take the approximate date of the scientific evidence of the existence of human species in an age of 2 million years.
With both numbers we can calculate the proportion in the scale of 20 thousand years throw the following formula:
PHS = 20000 years . 2 million years / 4500 million years = 8.9 years
PHS: Presence of Human Species
Answer:
(A) It connects Western and Central Europe.
(C) It is an important trade route.
(D) It is used for transportation.
Explanation:
The Danube is a river in central Europe and the second longest in this continent (the first is the Volga), which flows mainly through ten countries (Germany, Austria, Slovakia, Hungary, Croatia, Serbia, Romania, Bulgaria, Moldova and Ukraine) to finally flow into the Black Sea.
This river is of great importance for Eastern Europe because its channel serves as an international bridge for agricultural, fishing, tourism, commercial and industrial activities. In addition, the majority of the population that lives in its vicinity, depends on the water of the Danube to carry out its activities, which is why there is a large number of reservoirs and dams on its way.
Another important aspect is that the Danube has a high economic potential, due to its capacities for transport, commerce and tourism, so the use and use of its waters has been promoted.
Answer:
The age of seafloor rock increases as the distance from the mid-ocean ridge increases.
Explanation:
Mid-ocean ridges are a physical feature that occurs at divergent plate boundaries when the plate boundary is located in the ocean. This physical feature occurs because of more than usual intense activity in the upper mantle, resulting in cracking the crust and splitting up a tectonic plate, making the two, now divided pieces, to move away from each other.
The gap that is opening up between the plates is constantly filled with magma. The magma quickly cools off, creates new rock, and the rock piles up. This process goes on for millions of years, so the rock that has been formed initially has been pushed far away from the mid-ocean ridge by the constant creation of new rock, so the rock at the mid-ocean ridge is the youngest, while the more the distance increases from the mid-ocean ridge, the older the rock.
