How have CO2 concentrations changed in the past

What is the border between layers a through f and layer g called?

Which two nations are doing the most to combat their environmental issues?

Which of the following statements best describes east asia? a. east asia is known to be the crafle of civilizationb. east asia is one of the world's most populates placesc. east asia is one of the worlds riches placesd. east asia is located near the equator me asap huhu