Scientists<span> can tell by observing the seismic waves that are recorded all over the surface of the </span>earth<span> from distant earthquakes. The seismic waves are reflected (bounced off) </span>layers<span> of different density, and they are refracted (bent) when they enter </span>layers<span> of different density.</span>
Recently, Russia faces international conflict, especially about Venezuela Problems with EEUU.
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Triangular trade refers to the three legs of the trade system. -The first leg was the of trade was from Europe to Africa where goods were exchanged for slaves. -The second or middleleg of the trade was the transportation of slaves to the Americas
The age of the Earth is around 4.6 billion years old
