According to the diagram of the water cycle, what happens to the water in the oceans before it becomes water in the atmosphere?

The dissolved oxygen in a reservoir was monitored for one year. Based on this data, what might greatly reduce the available dissolved oxygen in an aquatic habitat?

Carbon dioxide is constantly exchanged among the atmosphere, ocean, and land. Carbon dioxide is produced and absorbed by microorganisms, plants, and animal by natural processes which help maintain a natural balance. However, since the beginning of Industrial Revolution, human activities have contributed substantially to Carbon dioxide gases in the atmosphere. Which conclusion might be drawn between the relationship found in the graphs of Global Carbon Emissions and Global Temperatures over the past 150 years.

Consider the aquatic phosphorus cycle. Phosphorus is the limiting nutrient for aquatic organisms. Decomposition naturally returns phosphorus to the aquatic cycle, but phosphates from fertilizers, sewage and detergents can cause pollution in lakes and streams. Over-enrichment of phosphate in freshwater can lead to __________ which, when they die and decay, leads to _____________.

The majority of Earth's atmosphere is nitrogen, N2. The percentage of nitrogen in Earth's atmosphere remains constant as prescribed by the law of conservation of matter and because it is a reasonably non-reactive gas. Like carbon, nitrogen is cycled through Earth's spheres. However, nitrogen can be converted into forms usable by plants and animals, either by lightning or bacteria. Once converted to usable forms, nitrogen is able to cycle the rest of the way through the ecosystem. Much like carbon, the recycling of nitrogen through Earth's spheres relies heavily on what type of organism?