More than 25,000 years ago, the first men (1) (arrive)________ on the continent(大陆) of America. These red-skinned men (2) (be)________ Asians, who (3) (come)________ from the far North in search of food. After 150 centuries (4) (pass)________, there (5) (be) ________ red-skinned men living in all parts of North and South America. Some tribes(部落) (6) (build)________ cities and great civilizations(文明). Their living on this continent (7) (become) ________ a milestone(里程碑) in human history. In 1492, Christopher Columbus, who (8) (look)________ for a new sea route(路线)to India, (9) (find)________ the land. He (10) (think) ________ it (11) (be)________ India, and (12) (give)________ the name “Indians” to the red-skinned people he (13) (see)________ there. Europe finally (14) (discover) ________ America.