<span>When frog matures from tadpole to adult, its gills are lost and develops functioning lungs. After maturity, frogs are still able to breathe through their skin---- known as “bimodal breathing,” wherein an animal uses two different systems for bringing in oxygen. These two different breathing systems allow adult frogs to shift between aquatic habitats (which require skin respiration) and land habitats (which are more suited to lung respiration).</span>
Answer:
I will say chemical processes
Because good researchers rely on first hand account or better said primary evidence. The reason why they rely on primary evidence is because it is usually the most reliable. Much more so than secondary or even tertiary evidence. This enables them to understand the history of a certain topic better.
