……………………………………………………………………………… d. Sight glass ?

A sight glass is a transparent tube or window used in industrial equipment to visually monitor the flow of liquids or gases. It allows operators to see the level, color, and clarity of the substance inside the equipment without having to open it up. Sight glasses are commonly used in pipelines, tanks, and other process equipment in industries such as chemical processing, food and beverage, and pharmaceuticals.

What is food