<span>The study of the physical features of the earth and its atmosphere, and of human activity as it affects and is affected by these, including the distribution of populations and resources and political and economic activities</span>
Answer:
Mesosphere
Explanation:
The mesosphere starts at 31 miles (50 km) and extends to 53 miles (85 km) high. The top of the mesosphere, called the mesopause, is the coldest part of Earth's atmosphere, with temperatures averaging about minus 130 degrees F (minus 90 C).
<span>Sinkholes, especially like the one that occurred in Mexico City, are often sign that the water reservoir is being depleted. Usually, the water underneath the ground helps stabilize it, however if there is suddenly open space or a cavern, it can collapse on its self causing a sink hole. This could also happen from fracking and drilling.</span>
