The common dolphin is a species of oceanic dolphin found in warm and temperate waters around the world.

The skin is the largest organ in the human body, covering an area of approximately 2 square meters.

The epiglottis is a small flap of cartilage that covers the opening of the trachea when swallowing, preventing food from entering the lungs.

Water is a compound made up of two hydrogen atoms and one oxygen atom, with the chemical formula H2O.

Gravity is the force that keeps objects on the ground and pulls them towards the center of the Earth.

A flow meter is a device used to measure the speed of a swimming pool by measuring the flow rate of water.

Polyvinyl chloride (PVC) is a material commonly used to make swimming pool lanes due to its durability and resistance to chemicals.

A pool vacuum is a device used to clean swimming pools by removing dirt and debris from the bottom of the pool.

Chlorine is a chemical commonly used to disinfect swimming pools due to its effectiveness in killing bacteria and other microorganisms.

A pool heater is a device used to heat swimming pools by raising the temperature of the water.

A pool cover is a device used to cover swimming pools to protect them from dirt, debris, and evaporation.

A pH controller is a device used to maintain the pH level of swimming pools by automatically adding chemicals to adjust the pH.

A water test kit is a device used to test the water quality of swimming pools by measuring the levels of various chemicals, such as chlorine, pH, and alkalinity.

A pool pump is a device used to circulate water in swimming pools, which helps to keep the water clean and free of debris.

A pool skimmer is a device used to remove debris from swimming pools, such as leaves, twigs, and insects.