31().

A. discovery
B. search
C. study
D. development

According to Crevecoeur, (26) settled in Pennsylvania in the 18th century, the American in those days had the mixed blood of Europeans or their descendants without (27) into consideration other nationalities (28) as American Indians and blacks. Today, the picture of an American is more complex. In American families, there may be sons-in-law or daughters-in-law with European descend ants or Afro-Americans or Asian immigrants although these mixed blood families of whites with other blacks or Asians are (29) the minority. To understand this American, let us go back to American past.

The American continents were peopled (30) a result of two long continuing immigration movements, the first from Asia, and the second from Europe and Africa. The first movement began probably 25,000 years ago when Siberian tribes, in (31) of new hunting grounds or of refuge from pursuing enemies, crossed over the Bering Strait to Alaska. By 1492, over 10 -20 million people, mistakenly (32) Indians by Christopher Columbus, inhabited the Americas. They developed their own aboriginal cultures, which ranged from the (33) the complex, from those of the primitive tribes to the brilliant civilizations of the Aztecs, the Incas and the Mayas. But their technological development had lagged (34) that of Europe and Asia.

The (35) migration to the Americas began with the expansion of Europe at the start of the modern period from the 16th century. In 1492, Columbus persuaded the king and queen of Spain to finance his voyage. He believed that by sailing west from Europe, he could reach the Far East. He never succeeded, but instead he landed on one of the Bahama Islands in the Caribbean Sea and "dis covered" the New World. Based (36) Columbus’s discovery, the Spanish king could claim the territory in the Americas and later Spain conquered the new land and established a huge empire and grabbed enormous wealth from the Indians. In 1497, another Italian sailor, John Cabot who was in the service of the English king, arrived (37) today’s Canada and the English king (38) that the whole of the territory of North America (39) to England. Enforcing this claim, the Englishmen be gan to (40) permanent settlements in North America by the beginning of the 17th century.