In what way was the rise of the umayyads and the rise of the abbasids diffrent

As a result of the columbian exchange, which crop was transferred to europe from the americas and later spread through the world? a coffee b maize (corn) c rice d olives e wheat

How did europeans and africans displace native americans in north america’s predominant peoples?

What do most climatologists see as a major cause of rising global temperatures? a. earth's closer proximity to the sun due to its gravitational pull b. greenhouse gases produced by burning fossil fuels c. rising ocean levels caused by melting polar ice sheets d. water pollution cause by industrial waste