A．Participator's figure．
B．Participator’s relative location to the obstacle．
C．Participator's reaction to the obstacle．
D．Participator's experience of parkour．

A．reducing energy waste during the process
B．making poses while moving at speed
C．fighting against someone blocking the path
D．preventing oneself from being injured or hurt

A．Tracers believe long-term effective practice Call help avoid injuries．
B．Beginners should train their endurance above all．
C．All parkour participators pay less attention to their safety．
D．Large drops are the most difficult techniques of parkour．