Convection takes place
a. warm air is more dense than humid air.
b. warm and cold air have the same densityc. cold air is less dense than warm aird. cold air is more dense than warm air

On venus, which of the following drives geological change? a. hurricanes b. volcanoes c. tsunamis d. earthquakes

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.

What events caused the united states to intervene in southwest asia?