Final answer:
False High-voltage transmission lines are not wrapped in insulation; the air serves as the insulator, and insulating connectors prevent the current from traveling down the towers.
Step-by-step explanation:
The statement that the high-voltage wires connected to tall metal-frame towers are wrapped in an insulating material is false. High-voltage transmission lines are not wrapped in insulation due to the high costs and impracticality of insulating such long stretches of wire. Instead, the air around the wires serves as an insulator, and the wires are held aloft by insulating connectors such as glass or ceramic insulators that prevent electricity from traveling down the towers to the ground.