Final answer:
The statement about high-voltage wires being wrapped in insulating material is false. While they are held by insulating connectors, these wires are typically bare because the air at high altitudes acts as an insulator.
Step-by-step explanation:
The question pertains to the characteristics of high-voltage wires and the materials used in their construction. The statement presented is false. High-voltage wires that are connected to tall metal-frame towers, commonly known as electrical transmission lines, are indeed held aloft by insulating connectors. However, these wires are not wrapped in insulating material. The reason for this is that at the high altitudes at which these wires are situated, the surrounding air acts as an insulator. Therefore, these wires are typically bare and without additional insulation to save on cost and weight, which would be impractical for such long distances.
On the other hand, the use of insulating connectors is necessary to prevent the electrical current from grounding through the towers. The insulation is crucial to ensure that the high-voltage electricity can travel over long distances without loss due to grounding or short circuiting with the tower structure.