Which acid is commonly found in vinegar?

Acetic acid

Who slew the Gorgon Medusa and later married Andromeda? What is the capital city of Bhutan? What is Rachel afraid of causing an episode-long fuss when she encounters one in her apartment? Who did Ross date after meeting her at Monica and Chandler's wedding reception? Which beloved Christmas ballet was adapted into a 1986 feature film starring Hugh Bigney?