Just like a compass, a modern day gps will say whether you're going north, east, south, or west, however they also tell your exact location and the location that you need to go too.
Answer:
Phytoplankton use carbon dioxide and produce oxygen during photosynthesis; phytoplankton, fish, and seals use oxygen and produce carbon dioxide during respiration. Which can provide the most energy in an ecosystem
Explanation:
