Where does most of the water vapor in the atmosphere originate? plants oceans glaciers snowfields

According to the earth science reference tables, during which geologic time period were the continents of north america,south america, and africa closest together?

The layers of earth are based on what two sets of characteristics?

17. the soil erosion pictured here is the result of what? a. harvesting renewable resources at a rate greater than the sustainable yield b. a mudslide caused by excessive rains c. harvesting renewable resources at a rate lower than the sustainable yield d. the transition between geologic eras and eons