run away是“跑开”“跑掉”的意思；run past是“跑过去”的意思.
例如：The little girl is so shy that she runs away when I want to talk to her.这个小女孩太害羞了,我刚想和她说话,她就跑开（掉）了.
It's impolite for drivers to run past people quickly on rainy and muddy road.在雨天泥泞的路上,司机开车飞快的从行人身边开过去（跑过去）,是很不道德的.