What results in the different angles of the sun during different periods?

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.

How does the bare soil surface type affect the amount of runoff

Read the article titled "castro resigns." why did the us impose trade sanctions against cuba in 1962?