What are cavities left in rocks when shells or bones dissolve?

Anybody who knows ap biology, can you friend or message me

Compare the composition of the moon's surface with the composition of the earth's surface.

Amarine ecologist has constructed the conceptual model shown in the diagram. what predictions can be made from using this model? where the tertiary consumers get their energy how often primary producers are able to reproduce when bacteria and fungi initiate the process of decomposition whether other secondary consumers are present