No organism can manufacture elements, such as calcium, magnesium, and phosphorus, so where do humans get them

Ausable water source is one that can be used by humans for drinking or agriculture. identify the water reservoirs as usable or unusable based on their current state. oceans rivers glaciers freshwater lakes groundwater

Identify the missing parts of the carbon cycle

Where do the respiratory and circulatory systems meet? a. in the heart b. in the muscles c. in the lungs d. in the brain