quickness       
noun [ U ] uk/ˈkwɪk.nəs/ us/ˈkwɪk.nəs/
 快速
the quality of being fast
  the quickness of his movements 他动作之快…… 
 her quickness to understand 她敏捷的悟性 
 See: quick
 - More examples
 - He had an obvious intelligence and quickness about him.
 - She is a young talent with exceptional strength and quickness
 - His quickness of mind is matched by his movement.