Scientists have used the fossil record, evidence of change, and mass extinction to develop which of the following time scales?

a. precambrian time scale
b. geological time scale
c. fossilogical time scale
d. earth history time scale

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.

The coco river is a natural border between nicaragua and which other country

In the figure, polygon abcd is transformed to create polygon a′b′c′d′. this transformation is a by a factor of .