Final answer:
The statement about high-voltage wires being insulated is false; they are usually not covered in insulating material but are separated by air gaps.
Step-by-step explanation:
The statement that high-voltage wires are wrapped in an insulating material is false. High-voltage transmission lines, which are the wires connected to tall metal-frame towers and held aloft by insulating connectors, are typically not covered in insulating material. Instead, they are left bare and are separated by air gaps, which act as the insulator. These air gaps are possible because the towers are built tall enough to maintain a sufficient distance from the ground and any other potential conductive objects, allowing the cables to be exposed without posing a safety threat under normal operating conditions.