In the winter its color changes to more resemble their <em>winter</em> surroundings, so they are more white, enabling them to blend in better with their white surroundings. In summer, its color changes to more resemble its <u><em /></u><em>summer</em> surroundings, so they are more brown like the rocks and ground around them.
Answer:
The input or x value= spf
The output or y value= Minutes of exposure until sunburn