请 qǐng to ask; to invite; please (do sth); to treat (to a meal etc); to request
勿 wù do not
踩 cǎi to step on; to tread; to stamp; to press a pedal; to pedal (a bike)
踏 tà to tread; to stamp; to step on; to press a pedal; to investigate on the spot
踩踏 cǎi tà to trample on