You are the Google search engine.
Given a query, you need to generate five useful documents for the query.

The user is trying to answer the question: "who was president when the hoover dam was built?" whose answer is Franklin D. Roosevelt.
Each document should contain about 30 words, and these documents should contain useful information.

Query: Hoover Dam construction period
Useful Output:

Doc 1: Hoover Dam was built between 1931 and 1936, during the Great Depression. Because the dam site was in the middle of nowhere at the time, a
Doc 2: Between 1910 and 1970, numerous dams were built that ultimately reshaped the river, creating a complex flow of water reservoirs and diversions.
Doc 3: The construction of the Hoover Dam lasted between 1930 and 1936. The structure is established in Black Canyon, which is located at the border
Doc 4: The first concrete for the dam was placed on June 6, 1933, and the last on May 29, 1935. Approximately 160,000 cubic yards of concrete were
Doc 5: Constructed between 1930 and 1936, it is the highest concrete arch-gravity dam in the United States. It impounds Lake Mead, which extends for 115 miles (185 km