How were horses reintroduced to North and South America in the early 1500s?
Spanish explorers brought horses to the New
World.
Plains Indians brought horses to make their
hunts more successful.
Horses were already living on every continent.
Plains Indians domesticated wild horses.

the federal government of the united states was established by the constitution. us is a presidential republic. the president is head of state, head of government and of a two party legislative and electoral system. the supreme court balances the powers of the federal and the state government. yhe executive branch is headed by the oresident. there are two chambers of congress, the senate and the house of representatives. judicial power is exercised by the judicial branch (or judiciary), comprised of the supreme court and lower federal courts. the judiciary's function is to interpret the   constitution as well as the federal laws and regulations.

answer; technology;

answer; american middle class;

answereruption of molten material; magnetic stripes in the rock of the ocean floor; the age of the rocks themselves;