How long can humans live without sleep?

What role do bacteria play in the carbon cycle

Match each description to the appropriate biome. tropical savanna desert tropical rain forest taiga tundra has sparse vegetation and very cold temperatures located near the equator and contains trees that form dense canopy layers is very hot and dry, and has plants that need little water has cold winters, heavy snowfall and is dominated by conifers has warm temperatures and is dominated by grasses

Models are non-visual ways of coummincating how someone thinks about something in the natural world