Why did greeks believe the earth as a sphere?

Which of the following regions has what is considered the most rugged terrain in oklahoma? a. the wichita mountains b. the arbuckle mountains c. the sandstone hills d. the ouachita mountains

Which characteristics are true of the arabian desert? multiple answers choose all answers that are correct. a. is mostly below sea level b. covers almost the entire arabian peninsula c. contains the largest sand sea in the world d. has very few people living there

What are the answers for the following questions?