I think the answer would be needs. Hope this helps.
Answer:
Classical conditioning
Explanation:
Classical conditioning or Pavlovian conditioning is conducted on living organisms to make them associate one or more actions to a given (often familiar) stimulus or stimuli. Ivan Pavlov, in his experiment, trained a dog to associate an action, salivating for food, with the sound of a metronome.
the sperm finds an egg and that egg equals a baby
