Which combination of technologies underpinned skyscraper construction?

Which combination of technologies underpinned skyscraper construction?

• A. Steel frame construction, fireproofing, and elevator technology
• B. Brick load-bearing walls and timber floors
• C. Stone masonry with no fireproofing
• D. Concrete domes and thatched roofs

Answer: (A)

The idea being tested is how tall buildings get their strength, safety, and practicality. Skyscrapers rely on a metal frame that acts as the skeleton, carrying most of the vertical loads so the exterior walls can be lighter and serve mainly as a facade rather than load-bearing. This steel frame needs fireproofing to protect the structure in case of fire, because heat can weaken metal and threaten stability. Elevator technology is essential because it makes moving many people quickly between floors feasible, turning a tall building from a curiosity into a workable workspace or residence. Together, these three elements—a strong, lightweight skeleton; fireproofing to safeguard the framework; and efficient vertical transit—make skyscrapers possible. The other options rely on heavy, non-skeletal methods or inappropriate materials that would limit height, safety, and practicality.

The idea being tested is how tall buildings get their strength, safety, and practicality. Skyscrapers rely on a metal frame that acts as the skeleton, carrying most of the vertical loads so the exterior walls can be lighter and serve mainly as a facade rather than load-bearing. This steel frame needs fireproofing to protect the structure in case of fire, because heat can weaken metal and threaten stability. Elevator technology is essential because it makes moving many people quickly between floors feasible, turning a tall building from a curiosity into a workable workspace or residence. Together, these three elements—a strong, lightweight skeleton; fireproofing to safeguard the framework; and efficient vertical transit—make skyscrapers possible. The other options rely on heavy, non-skeletal methods or inappropriate materials that would limit height, safety, and practicality.