What was a reason Tribal people from the Great Plains developed a sign language?

A.
Native people of the Great Plains all spoke the same language.
B.
Some Native people wished to trade with nations speaking other languages.
C.
Tribal nations of the Great Plains did not want to speak to Spanish colonists.
D.
Native people of the Great Plains had beautiful hands.

a social contract.

"a social contract is an agreement between citizens and their leader where the citizens give up certain freedoms in exchange for protection. the constitution of the united states is an example of a social contract."

the outcome of 1970 oil crisis in united states was that, they began to search ways on how to reduce oil.

in 1970 was a period when there were energy and oil crisis. those who were major centers for industrialization were forced to keep way from supplying of petroleum.

some of the result of this crisis was economic growth became stagnant because prices of oil surged.

due to the increased prices some countries like mexico and norway benefited.

living during the great depression had a major affect on the mentality many people. a good portion of people who lived during that time do not trust banks. this is likely the result of the many widespread bank failures in the 30s that caused people to lose their life savings.