What do contour lines that form a circle represent on a map?

Renewable resources of west and central africa include:

In a 2010 article “fact check: eastern u.s. earthquake risk” by chris mould, the author provides as evidence the following statement by the united states geological survey: “although earthquakes may be less frequent in the eastern u.s., … urban areas in the east could face bigger losses because the shaking would affect much larger areas than similar quakes in the west. in addition, most homes and buildings in the east are not designed to withstand earthquakes.”this statement directly relates to which of the following concepts? a. vulnerabilityb. hazardc. riskd. severity

What major factors play a role in global warming? 1. human activity and normal climate conditions 2. natural factors and human activity 3. normal climate conditions and abnormal human activities 4. abnormal human activities and natural factors