At the end of the paleozoic era, there was a mass extinction that wiped out over 90% of all species. what was the possible cause of this mass extinction and why did it cause so many organisms to become extinct?

Combine like terms. do not forget to use the distributive property to simplify the first term. 2(3y + 5k) - 2k

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.

An enormous wave generated by an earthquake beneath the seafloor is known as a