The form of a word that is used to denote more than one
acknowledgement, acknowledgment - a statement acknowledging something or someone; "she must have seen him but she gave no sign of acknowledgment"; "the preface contained an acknowledgment of those who had helped her.

Hi

Greeting is an act of communication in which human beings (as well as other members of the animal kingdom) intentionally make their presence known to each other, to show attention to, and to suggest a type of relationship or social status between individuals or groups of people coming in contact

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