What are the main boundaries that define sub-sahran africa?

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.

Which example gives the relative location of a place? 50 main street 33 degrees n latitude, 91degrees w longitude east of the library 1600 pennsylvania ave., washington, d. c.

Acharreadas is a popular mexican thing where people display varying skills of horsemanship much like what events in the united states?