Which are used to measure distances north or south of the equator?

What part did glaciers play in forming the great lakes?

The mantle is made up of which structural zones?

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.