Which are causes of mechanical weathering? Select three options.

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 of the following is a way that advancements in technology improve humans' ability to measure air quality and protect human health?

How much water is in the ocean in cubic kilometers