Which of the following was a major milestone that allowed for greater diversity of life during the paleozoic era? reptiles became more diverse. many marine animals went extinct. photosynthetic prokaryotes produced more oxygen. animals moved from the sea to the land.

i believe it is "they are not used up by reactions" as the answer to your question, text me back if this is correct because i just learned this.

trachea, alveoli, lung capillaries, arteries

and after water is usually warmed by the sun the water temperature raises and then evaporates .