The conversation between human and AI assistant.
[|Human|] Identify which of the following items are non-verbal communication.
[|AI|] Among the given items, two of them are non-verbal communication: Gestures and physical distance. Vocal tonality, on the other hand, refers to the way that the voice is used and can convey emotional states, pitch, but is still verbal communication.
[|Human|] 
Identify which of the following items are non-verbal communication.