How do chelating agents help solubility cell walls

When analyzing tree rings, what do scientists assume a thin ring indicates?

Several bird species feed in a certain species of tree. each bird species feeds in a different part of the tree. which statement is true of these bird species? a. they have adapted to different niches due to competition b. they have a carnivorous relationship with the tree species. c. they have adapted to different niches due to predation d. they have a symbiotic relationship with the tree species.

What is the difference between a scientific hypotheses and a scientific theory?