1 and 2 because its nature
Explanation:
Urban Population Density, Climate Change, and Disasters The dense concentration of urban populations can increase susceptibility to the disasters that are likely to become more frequent and more intense as a result of climate change. Many aspects of urban areas are vulnerable to disasters and climate change.
The coolest layer is the crust. The crust is on the surface of the earth (where we are) . Inner Core
A planetary nebula is a (ring-shaped) type of nebula formed by an expanding shell of gas around an aging star. *a planetary nebula is a type of nebula*. im not completely certain though. i might be wrong.
