With the     1    of economy, how to balance progress     2     the protection of cultural heritage is a big challenge. Great solutions,    3     ，tend to arise from the challenges. In 1950s, in order     4     control the flooding, the Egyptian government made a proposal to build a new dam across the Nile. It would cause the water levels to rise high enough to flood     5     number of ancient temples,     6     were among Egypt’s cultural heritage. So the government turned to the United Nations for help. Soon an international committee was     7     to help Egypt to find the solution.     8    , they made a decision that all cultural    9     should be removed. The project was considered a greatly successful example by UNESCO to prevent world heritage     10     disappearing.