Using the cross section, explain how the geologist knows the relative age of the intrusion compared with that of
the gravel.
Then, explain how the geologist knows that the flow is older than the intrusion.

Idk little ngr try paying attention in school and you would know ngr

When scientist examine data such as historical documents, they are using the "scientific methods"

Although i don't know what is the simulated system, starfish are predators that eat mostly  microalgae,  snails, sponges, bivalves, mussels and other small marine animals. removing starfish from any system would definitely increase this animals that they prey.