which source reflects the highest degree of authority on the subject of shale-oil deposits in north america?

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

Asap will mark geography final plz ! what are the benefits of international aid? (give me the right evidence )

What is the difference between the cultures of central asia and the caucasus region? the majority of people in central asia are muslim; the majority in the caucasus region are christian. the primary language in central asia is armenian; the primary language in the caucasus region is russian. central asia has been plagued by ethnic unrest; the caucasus region has had little ethnic conflict. the effects of soviet rule can still be seen in central asia; the caucasus region has developed its own identity since the fall of the ussr.