What is the layer of permanently frozen subsoil in the tundra?

What is the orange line on the graph and why is it important? describe the pattern of hurricanes reaching the usa since 1960

Which measure of humidity, relative humidity or dew point, best describes the actual quantity of water vapor in a mass of air

The pyramid has a square base that us inscribed in the circular base of the cone. draw an image of the composite shape of the base. 2) if the side length of the square base is 8 units long, what is the diameter of the circular base of the cone from the picture in number 1