What were native american groups most threatened by?

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

How did american entry into world war i affect the allied powers?

What was the significance other than the obvious harm to us forces of the terror attack on the uss cole in 2000

Me i really need which of these was an accomplishment of the han dynasty? the invention of the seismograph finding a water passage to europe the invention of the ballpoint pen the invention of the abacus