How many time zones are there total if you count from Alaska to the Eastern Standard Time Zones ?

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.

Rainbow trout is non- native to the united states. however this species is breeding with the native gula yltrout acientistrecently observed that the hola trout were becoming exitinct what is the cause of their extinction

Mexico city is an example of how humans alter their environment because it was a. one of the world’s largest cities b. built on drained and filled lake beds c. built after conquest by the spanish d. once the capital of the aztec empire