Can someone please help me?​

The formation of business monopolies in the late 1800s was made possible by the (1) effects of laissez-faire policies (2) passage of federal antitrust laws (3) elimination of the free-enterprise system (4) adoption of socialist economic practices

Those who resisted the mongol invaders were attacked and their towns burned; those who cooperated with them also were attacked and had their towns burned. were treated fairly. were taken into the tribes and treated as mongols. were sent away to find new homes.

Which of the following was probably the most difficult challenge facing construction of the railroad?