Tag: science & technology

Iron is the correct answer. The Eiffel Tower is constructed from puddled iron (wrought iron), not steel. When built in 1889, iron was chosen for its strength and workability. The tower contains approximately 7,300 tons of iron and requires regular maintenance with paint to prevent rusting.

Spanish explorer Garcia Lopez de Cardenas, a member of Francisco Vasquez de Coronado's expedition, became the first European to see the Grand Canyon in 1540.

Shi Huangdi (Qin Shi Huang) unified China in 221 BCE and ordered the connection of existing fortification walls from various warring states, creating the first version of the Great Wall. While walls existed before, he is credited with organizing and connecting them into a unified defensive system.

The Empire State Building is located in Midtown Manhattan, New York City. It was completed in 1931 and stood as the world's tallest building for nearly 40 years. The other options are all states, not specific cities, and are incorrect locations.

The Golden Gate Bridge connects San Francisco with Marin County across the Golden Gate strait. The bridge opened in 1937 and spans approximately 1.7 miles. Marin County is located just north of San Francisco.

The Golden Gate Bridge, constructed between 1933 and 1937, cost approximately $35 million to build. In today's dollars, that would be well over $500 million. The bridge was financed through bonds and was a major engineering feat of its time.

The Shanghai Maglev is the world's fastest commercial train service with a top speed of 431 km/h. The other options are either not operational (Super 574) or not actual train names.

The Suzuki Hayabusa is recognized as the world's fastest production motorcycle. The other options (Bullet 2010, Tomahawk, Yamaha Z 500) are either not the fastest or not actual production models.

The Lockheed SR-71 'Blackbird' remains the fastest air-breathing manned aircraft in history, capable of speeds exceeding Mach 3.2. The An-225 is the largest cargo plane, and 'boing' (Boeing) is a manufacturer, not a specific plane model.

The Bugatti Veyron is the world's fastest production car. The other options (Nano, CRV-HS, Vauxhall Victor) are either budget cars or not designed for top speed records.