Atype of government in which all key powers are given to a national or central government

What did europeans build much of during the eleventh and twelfth centuries? ?

Yo i need a catchy title for an article about the importance of the fourth amendment

How did the completion of the transcontinental railroad change the lives of american citizens? a-it increased the wealth of all americans and enabled them to travel more. b-it made cross-country travel too expensive for ordinary americans. c-it decreased the safety of americans who moved to settle the plains. d-it shortened travel time between the east and west for all americans.