The history of the American people is,【C1】______, the history of the movement of the Ameri

can people. They moved from the colonies of the East Coast to the open space of the【C2】______They moved from the country and the farm to the city.【C3】______, Americans have been moving from the cities to the suburbs. Pioneer Americans began【C4】______from the East Coast to the West 250 years ago. They moved west for many reasons.【C5】______reason was that they could obtain【C6】______open space and land【C7】______fanning. Americans liked large open spaces, and they liked the freedom and independence to【C8】______the land in their own way. Some of the land became farms. Important minerals were discovered in some areas, so some of the land became【C9】______Other large areas became cattle ranches. There seemed to be enough land for everybody. But it was a difficult【C10】______of endless work and hardship.

【C1】

A．with part

B．of part

C．in part

D．on part