What is necessary for a convection cell to be set up in a fluid? thermal gradient and changes in density

thermal gradient

changes in density

Which of the following is not a challenge to instituting sound global environmental policies? a. most changes are inexpensive and easy to implement. b. elected leaders who support unpopular environmental issues often are not re-elected. c. economic considerations outweigh environmental ones in many societies. d. there is no way to enforce international environmental agreements.

According ti the following map, what are the most common mineral resources found in the united states?

Where was oil production at its highest in the 1980s and still remains important to the russian economy? central asia the ural mountains russian siberia the caucasus region