"Nation'as a free root can function alone in a sentence while "dict" is a ______ which can not function alone grammatically and has to combine with other morphemes to create new words.

A．wheat prices are very low in the world
B．the demand for wheat is decreasing
C．many regions are affected by drought
D．the wheat consumption is becoming less

A．The duality that characterizes the consciousness of modern Black Americans is so deeply rooted that it cannot be eliminated by political action.
B．African captives who were brought to North America had learned a basic orientation toward the world which remained with them.
C．At the time of the beginning of the United States, white Americans were not aware of the contradiction between the notion of equality and the institution of slavery.
D．The influence of the slavery experience on the West Africans was more powerful than the memory of West African attitudes.