Acatastrophic disturbance that resulted in mass extinction marks the boundary of which two eras? a. precambrian time and paleozoic era b. paleozoic era and cenozoic era c. mesozoic era and cenozoic era d. none of the above

Which describes interactions between substances and stomata during photosynthesis? check all that apply. oxygen enters stomata. oxygen is released through stomata. carbon dioxide enters stomata. carbon dioxide is released through stomata. hydrogen enters stomata. hydrogen is released through stomata.

Arollercoaster car at the top of a hill has potential energy kinetic energy chemical energy light energy

What layer of the atmosphere is directly above the troposphere?