What were native american groups most threatened by?

buffalo herds
other native american groups
drought
diseases introduced by white settlers

The chart shows data on the construction of dreadnoughts, or armed battleships, by 1914. (look at chart provided) a logical conclusion that can be drawn from this chart is that britain and germany were a.)engaged in an arms race. b.)looking for ways to cooperate. c.)hoping not to fight on land. d.)the strongest nations on the earth.

Human rights groups in the 20th century worked to: o a. european imperial powers maintain control over their colonies. o b. convince citizens in impoverished countries to embrace nationalism. o o o o c. ensure that people around the world were protected from brutal treatment. o d. weaken the influence of international organizations like the united nations. sub

The information box says that the han added 4,000 miles of wall.refer to the mileage scale.how can this be true?