What are the two main causes of soil pollution

Is there any species that went extinct in recent years due to natural causes (not caused by human interaction). if so, what caused it?

Explain how paleontologists use trilobite fossils as index fossils for various geologic time periods.

Membrane vesicles containing an internal sodium chloride (nacl) concentration of 0.14 m are placed into separate beakers each containing a different solution. the first beaker contains 0.14 m sucrose, while the second beaker contains 0.14 m calcium chloride (cacl2). the temperature is 25°c. what is the solute potential inside the vesicles, expressed in units of mpa?