Warm surface waters get depleted of nutrients and carbon dioxide, but they enrich again as they travel through waters in the conveyor belt. The base of the world's food chain depends on the cool, nutrient-rich waters that support algae and seaweed.
One choice

saline

shallow

deep

freshwater

the leaf is an organ of a typical plant, and the main functions are to complete photosynthesis and allow the plant to exchange gas, just like how we have the respiratory system. leaves have the stomata, which collects maintains co2 and o2 levels. this is necessary for cell metabolism. the leaf also collects sunlight using chloroplasts. succinctly, leaves own a pivotal role in sustaining plant life.

i just calculated it all out, and not including weekends, and all the different days off. as of this school year (2018-2019) students are spending 2198 hours in school this year