In years the Yellowstone super-volcano will erupt and affect the entire earth.

7. according to the theory of isostasy, which statement must be true? a. the asthenosphere is denser than the lithosphere. b. the asthenosphere has the same density as the lithosphere. c. the lithosphere has the same density as the core. d. the lithosphere is denser than the asthenosphere.

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.

This phrase from the declaration of independence and its primary author thomas jefferson can be used to justify which statement? a) jefferson thought this document could be used in his defense were he put on trial for treason. b) jefferson knew that the colonists' actions would have an international impact. c) jefferson believed that a bill of rights was necessary in the new government. d) jefferson was trying to show the king that the colonists were intellectuals.