Answer: C. 30 - 50 million years ago
Explanation:
Fossils found in layer Y formed 30 million years ago according to the graph above. Similarly, fossils found in layer Z formed 50 million years ago.
If a fossil (fern fossil) is found between layer Y and layer Z, it means that it formed between the years that the fossils in layers Y and Z formed which is 30 - 50 million years ago.
Tobias drank from a contaminated water fountain
Darwin made numerous observations and collected evidence that led him to purpose a revolutionary hypothesis about the way life changes over time. I hope this helped :)
When obtaining the health history from a client with retinal detachment, a nurse expects the client to report FOR SOME ISSUES RELATED TO EYE SUCH AS LIGHT FLASHES AND FLOATERS IN FRONT OF EYES.
Retinal detachment is a medical condition where the retina is pulled away from the blood vessels that supply blood and oxygen. If not treated timely, it can lead to permanent loss of eye sight.
The only way for gases to diffuse in and out of the leaf is through small openings on the bottom of the leaf, the stomata.