Why can scientists not always divide a period into epochs

Which of the following would be an important part of a multi-step plan to restore the stability of the red-cockaded woodpecker's ecosystem?

What controls activities within a eukaryotic cell?

The bacteria in the human gut feeds on the food we eat and us break it down for better digestion. what does this exemplify? (a) predator-prey cycle (b) parasitism (c) mutualism (d) a disrupted food chain