Final answer:
The statement is false; high-voltage transmission lines are supported by insulators but are not wrapped in insulating material; instead, air and distance serve as the insulator.
Step-by-step explanation:
The statement that high-voltage wires connected to tall metal-frame towers are held aloft by insulating connectors and are wrapped in insulating material is false. High-voltage transmission lines are indeed supported by towers and held by insulating connectors, or insulators, that prevent the electricity from flowing to the ground. However, these wires are not wrapped in insulating material. The air and distance serve as the insulator, considering the high voltage at which the electricity is transmitted. The design of these transmission systems takes into account the necessary clearance from objects and the ground to prevent arcing and maintain safety.