[简答题] The timing, route and point of origin of the first colonization of the Americas remains a most arguable topic in human (47)______. However, a new theory claimed that a "LOST TRIBE" that reached America from Australia may have been the first Native Americans. If proved by DNA evidence, the theory will shatter long (48)______ beliefs about the southerly (49)______ of people who entered America across the Bering Strait, found it empty and occupied it. On this theory rests the authority of Native Americans (previously known as Red Indians) to have been the first true Americans. To a European, this may seem like an academic (50)______, but to Americans it is a philosophical question about (51)______, Silvia Gonzales, of Liverpool John Moores University said. She argued that there were several migration waves into the Americas at different times by different human groups. Her claims are based on (52)______ found in the Baja California Peninsula of Mexico that have skulls quite