Question

which is one piece of information that fossils in samples from earths crust reveal about earths history?
changes in climate
number of species at a specific time
composition of earths core
age of organisms when they died

Explanation:

Fossils in Earth's crust can show the number of species present at a particular time. Changes in climate (while related to Earth's history) is a broader environmental factor. The age of organisms when they died is more about dating individual fossils. The composition of Earth's core is not revealed by fossils in the crust. So the number of species at a specific time is the most relevant information that fossils in Earth's crust can reveal about Earth's history.

Answer:

number of species at a specific time