Discuss how water is replenished in sea.

Water is replenished in the sea through water cycle in nature.

Water in the atmosphere is converted into water vapor by the heat from sunlight i.e. water evaporates and turns into water vapour. Also, water vapour is present in the atmosphere from plants by transpiration from leaves. This water vapour condenses in the atmosphere and forms cloud. When enough water vapour has condensed, it falls down on earth in the form of rainfall. This water either seeps underground or flows into sea, rivers or lakes, thus replenishing the water that had evaporated by heat from sun.