填空题 Questions 21-27
Complete the summary below.
Choose NO MOPE THAN TWO WORDS from the passage for each answer.
Write your answer in boxes 21-27 on your answer sheet.

Eduardo Neves has carried out his research on Amazon culture for 17 years who first thinks the disappearance of{{U}} {{U}} 7 {{/U}} {{/U}}is understandable because ancient people built their towns only with{{U}} {{U}} 8 {{/U}} {{/U}}. But the discovery of{{U}} {{U}} 9 {{/U}} {{/U}}challenged his way of thinking and this means those people have already abandoned the lifestyle of{{U}} {{U}} 10 {{/U}} {{/U}}because they could not take large containers on the way. And another problem on vanishing civilization could be partly solved by hypothesis that diseases brought by{{U}} {{U}} 11 {{/U}} {{/U}}have destroyed it. Although the study of lost Amazon civilization is hard to imagine for early explorer, thanks to the help of{{U}} {{U}} 12 {{/U}} {{/U}}, modern scientists have found 28 towns which were connected with roads and{{U}} {{U}} 13 {{/U}} {{/U}}.