助跑

助跑	zhù pǎo	to run up (pole vault, javelin, bowling etc) / approach / run-up / (aviation) takeoff run
助	zhù	to help / to assist
跑	páo	(of an animal) to paw (the ground)
跑	pǎo	to run / to run away / to escape / to run around (on errands etc) / (of a gas or liquid) to leak or evaporate / (verb complement) away / off