What is a period of unusually high temperatures called

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

:calculate the sum of the interior angles of a 13-sided polygon.

All of the following statements about the biosphere are true except: a. light and heat from the sun do not affect the biosphere. b. the biosphere gets resources from earth's crust, hydrosphere and atmosphere. c. like "biology", the name for the biosphere comes from the greek word for life. d. the biosphere includes all living organisms on earth's surface.