英文關鍵字
action
active
bicycle
bicycling
bicyclist
bike
biker
biking
bmx
boy
cycle
cyclist
dangerous
dirt
downhill
extreme
fast
floating
free
freestyle
helmet
jump
leaping
lifestyle
male
man
motion
mountain
mtb
nature
one
outdoor
people
person
play
ramp
recreation
ride
risk
silhouette
sky
speed
sport
sports
street
teenager
trial
trick
young
youth