Which cycle is essential for providing clean, fresh water?

Which cycle is contributing to global warming because of human activities?

Which cycle is contributing to acid rain because of human activities?

How do humans get the nitrogen they need to produce proteins?

What type of plants are useful for taking nitrogen out of the atmosphere and converting it to nitrate, a form plants can use?

Which process allows carbon to be locked away for thousands, even millions of years?

How can that carbon (from previous question see below) be released?

Which process allows carbon to be locked away from thousands, even millions of years?

Which is NOT a basic step of the water cycle?

What happens if there is too much carbon dioxide in the atmosphere?

What process releases energy to cells and then releases carbon dioxide and water back to the atmosphere to be used again?

Hydrological Cycle #1

Hydrological Cycle #2

Hydrological Cycle #3

Hydrological Cycle #4

Hydrological Cycle #5

Hydrological Cycle #6

Hydrological Cycle #7 (arrow with no number)

Hydrological Cycle #8