[填空题]The traditional American Thanksgiving Day celebration goes back to 1621. In that year a special feast was prepared in Plymouth, Massachusetts. The colonists who had (47) there had left England because they felt denied of (48) freedom. They came to the new land and faced difficulties in coming across the ocean. The ship which carried them was called Mayflower. The North Atlantic was difficult to travel. There were bad storms. They were assisted in (49) to live in the new land by the Indians who inhabited the region. The Puritans, as they were, had much to be (50) for. Their religious practices were no longer a (51) of criticism by the government. They learned to (52) their farming habits to the climate and soil. When they selected the 4th Thursday of November (53) their Thanksgiving celebration, they invited their neighbors, the Indians, to join them in dinner and a prayer of (54) for the new life. T