The Rio Grande is not shared by the United States and Canada.
They do not occur only during spring they occur when the sun, moon, and earth are all alined.
GDP, which we use right now, to see how many people have jobs, at what income, to decide how good the economy is. We could possibly use population density, as poorer countries/less developed countries tend to be more dense all around. Mainly economic things though, so GDP, income per capita. We use life expectancy, rate of literacy, freedom index..hope this helps
Answer: B
Explanation:
Volcanoes typically occur underground when they do. "Although most of the active volcanoes we see on land occur where plates collide, the greatest number of the Earth's volcanoes are hidden from view, occurring on the ocean floor along spreading ridges." (https://oceanservice.noaa.gov/facts/volcanoes.html)
