Steel made it possible to build Skyscrapers. Answer "construction of skyscrapers"
very possible
Steel
Steel.
it was Electricity
Steel companies make steel bars in hexagons
Steel companies make steel bars in ovals
Steel companies make steel bars in squares
Steel companies make steel bars in circles
skyscrapers
steel
Steel is made from iron. We combine a small amount of carbon with iron to get (make) steel.