What natural barriers blocked East from West on the Silk Road?

When does a metropolitan area become a megalopolis?

Where do most people in arabia and iraq live? a. in the fertile crescent b. in the rub, al-khali c. in cities d. in and around mecca

This data best supports which thesis about the causes of the french revolution? a. the first estate wanted to protect themselves from the second estate. b. the third estate resented the amount of taxes they paid. c. the first estate resented the amount of land they owned. d. the third estate thought they could overwhelm the rest of the country.