Which term means airtight; impervious to external influence; completely sealed by fusion or soldering?

• A. Hermetically Sealed
• B. Head Panel
• C. Hinge Cover
• D. Grave Liner

Answer: (A)

The term describes an airtight, impervious-to-external-influence seal achieved by fusing or soldering. Hermetically sealed means no air or contaminants can enter because the seams are joined into a continuous barrier, often through fusion or soldering. This precise sense of a flawless, airtight enclosure is why it fits the description best.

The other terms refer to hardware or containers that do not inherently convey airtight sealing. A head panel and a hinge cover are components, not measures of airtight integrity, and a grave liner is a burial container whose purpose isn’t to be airtight in the sense of fusion-sealed joints.