Final answer:
The statement about PEX piping and shielded couplings is true, as PEX piping can be coupled using shielded couplings.
Step-by-step explanation:
The statement that PEX piping may be coupled together with shielded couplings is true. In plumbing, PEX (cross-linked polyethylene) piping is indeed commonly used for various applications such as water supply lines, and plumbers may use shielded couplings or fittings to connect segments of PEX piping. Shielded couplings are designed to maintain the integrity of the connection while also protecting from external elements and any potential leakage.
However, this question appears to be related to a different statement about high-voltage wires and insulation that is part of the actual assignment. It is important to address the correct statement: The high-voltage wires connected to tall metal-frame towers (electricity pylons) are not wrapped in insulating material; rather, they are held aloft by insulating connectors. Therefore, the statement is false. High-voltage wires are bare and are insulated by the air surrounding them and the insulating connectors that attach them to the pylons.