Book 25, Question 16
What is on the roof of a skyscraper?
A skyscraper roof is crowded with equipment.
There are machines for elevators, big fans and cooling units for air conditioning, antennas for radio and phones, and sometimes water tanks. There may be a rig for window washers, lightning rods, and red lights to warn airplanes. Some roofs have gardens, solar panels, or a helicopter landing area.