Fill in the blanks with the words from the box.Until the middle of the 19th it was almost to construct tall buildings because and stone had to carry the weight of the . The Industrial Revolution and the of iron and steel made it possible to build strong and light . They were able to very tall buildings. Elevators could carry many people to higher stories very quickly.As cities grew higher more and more people could live and work there. Skyscrapers were seen by many as a way to save land but they were also thought of as a of power and importance. For decades American cities had the title of the world’s tallest building. The Empire State Building became a of New York and was the world’s tallest building for four .Today, the world's tallest structures are being built in the Middle East and eastern Asia . Currently, the largest in the world is the Burj Khalifa, an 800 metre high structure that contains apartments, stores, restaurants and other .