Which river formed the grand canyon?
a.

the columbia
b.

the colorado
c.

the rio grande
d.

the mississippi

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