Answer:
Aryans moved from the area of todays Afghanistan to the Indian subcontinent during the period of Indo-Aryan migration, somewhere around 1800 and 1500 BC.
Explanation:
Some scholars don't agree with this theory that the Aryans migrated to the Indian subcontinent, but most of historians are arguing that during this migration they came from the North and destroyed the Dravidians who were living there. Their period that started during the migration is known as Vedic period.
Answer:
Cold, dry
Explanation:
Humid air is often more associated with tropical climates, and we can assume from "polar" that the answer would be cold.
<h2>Right answer: The density of Earth's layers</h2>
The Earth is basically made up of layers, with the Earth's crust being one of the last layers (the surface on which we stand). However, <u>this crust is not continuous, it is composed of pieces called</u><u> tectonic plates</u><u>, and the places where these plates joint together are called </u><u>faults.
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When theses tectonic plates move or when sudden displacements in faults or cracks in the interior of earth’s crust occur; seismic waves are originated.
The seismic waves are the propagation of disturbances generated by small movements in a medium, <u>they propagate towards the earth's surface</u> causing earthquakes or low intensity seismic movements.
Now, <u>the speed of the waves</u> depends of the properties of the medium; which are fundamentally:
(1) the elasticity and (2) <u>the density</u> of the materials by which it is propagated.
<h2>Therefore, according to the speed of the seismic wave, the density of the Earth layer can be found.
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