<span>His opportunity cost is to give up the next best thing, in this case the digital camera. It is called a trade-off between cell phone and digital camera. But I could not imagine that it is a big one, compared to efficiency and equality.</span>
Human and physical (look up the definition.)
Animal fats. blame brainly for this one
Tropical places are hot because the humidity coming from the moisture of the plants and water are heated by the sun on the top layer of the tropical zone. The climate varies little in rain forest. There are five layers in the tropic trees so it's so thick that barely any light come through. This is also why vines grow up the trees so they can reach the sunlight to get nutrients. Also, the tropics are near the equator and that also causes the heat. The polars are cold because they barely get any sun heat to melt the snow or warm it up. The polars are melting due to certain chemicals and gasses in the atmosphere. also known as global warming. Hope that was helpful!