Earth has a tremendous amount of water. So why is water sometimes a scarce resource? What are the reservoirs for water?
What is residence time? What does it mean to say the residence time of water in the atmosphere is nine days?
According to the video, how much of Earth's surface is covered with water? What is most of this water in?
According to the video, what percent of Earth's water is salty? How much is fresh water?
According to the video, of all of the freshwater, what percentage is ice, what is shallow groundwater, what is deep groundwater, what is in lakes and rivers and what is in the atmosphere as water vapor?
According to the video, how much of Earth's freshwater is available for human consumption?
How does the use of repetition affect the narrator’s tone in this passage