Answer: 4. They can be used to help date layers of rocks around the world
Explanation:
A useful index fossil must be distinctive or easily recognizable, abundant, and have a wide geographic distribution and a short range through time. Index fossils are the basis for defining boundaries in the geologic time scale and for the correlation of strata.
Their poverty costs the country and the world through the loss of the island's endemic biodiversity. Madagascar's major environmental problems include: Deforestation and habitat destruction. Agricultural fires.
I would say C because our body is continuously changing through puberty. We need more sleep, more food consumption, we need to have fantastic hygiene, etc...
