How did the geocentric theory change over time as increased scientific knowledge lead to increase consensus within the scientific community

What is the approximate circumference of the circle shown below? 12.2 cm

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.

Hey, i was what is consisted in a sustainable city? like what unique designs they have, etc. for answering ; )