听力题 Columbus sailed from Spain in September 1492, looking for gold. Native Americans greeted him, offering some corn. He found little gold on that trip, but he collected many plants including corn to bring back to Spain. Columbus didn''t know it. But the corn was much more valuable than gold. Farmers from Europe to Asia accepted it immediately. They grew it on cold mountain sides and in tropic forests. Today it feeds millions of people all over the world. On his second trip, Columbus brought back a few chocolate beans to make chocolate. Europeans and Asians loved this new drink, and soon they were paying a great deal of money for the beans. Chocolate beans became so valuable in central America that they were used as cash for two hundred years. Tomatoes and potatoes took some time to become popular. Eventually, however, they became the basis of a lot of popular foods. It''s hard to imagine life without potatoes or chocolate. Thanks to native American cultures, many people are able to enjoy a lot of tasty foods.