Four; the upper atmosphere, the atmosphere, the mantle, and the core.
Answer:
Four satellites are needed to find your location. GPS's get the signal from satellites and that can calculate the distance you are from those satellites and location. the satellites emit high frequency low power signals that your GPS can pick up.
Explanation:
Answer:
My guess would be H₂O/ water, since osmosis is a form of passive transport and I can't see the model the question references. Gases like O₂/ oxygen, CO₂/ carbon dioxide, and simple sugars like glucose can also pass through a cell membrane with passive transport though.
