How can a geological time scale best be reconstructed?

Explain why in any given geographical region, women tend to have lighter skins( by 3-4% on average) than men?

The skeletal system performs a variety of functions that are crucial to maintaining life processes. what function is performed in the bone marrow, but not in the ossified bones of the skeleton? a oxygen transportation c mineral storage b. muscle attachment d red blood cell production

This is the interaction of two organisms where one is and the other is neither nor harmed.