Answer:
5 examples of internal structure of the earth are:
1) Crust.
2) Upper Mantle.
3) Lower Mantle.
4) Outer Core.
5) Inner Core.
5 examples of external structures of the earth are:
1) Exosphere.
2) Thermosphere.
3) Mesosphere.
4) Stratosphere.
5) Troposphere.
(c) The countries of south America and Africa
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Answer:
The most recent eon is subdivided into three eras and eleven periods.
Explanation:
The geological time scale has been constructed so that it can help in better research and understanding of the past, as well as making it easier to distinguish the past and its characteristics at a certain time. There are larger and smaller divisions in the geologic time scale, with the eon being the largest unit, followed by era, and then period.
The most recent eon is the Paherozoic, starting from 542 million years ago and still going on. It is subdivided into three eras and eleven periods so far. The three eras are:
- Paleozoic
- Mesozoic
- Cenozoic
The eleven periods are:
- Cambrian
- Ordovician
- Silurian
- Devonian
- Carboniferous
- Permian
- Triassic
- Jurassic
- Cretaceous
- Tertiary
- Quaternary
