Why did revolutions sweep across europe in 1848?

According to thomas hobbes concept of the social contract, what do people exchange for the protection by the government?

Historians believe that animals drawn in cave paintings during the paleolithic era could have represented each of the following except a a. successful hunt b. domesticated pet c. god that was worshipped d. way to obtain an animal's spirit select the best answer from the choices provided

Who was the first present of the united states