英文關鍵字
action
active
adventure
bicycle
bike
biking
brakes
cliff
climb
close
cycle
cycling
cyclist
forest
hard
hill
impassability
impassable
male
man
motion
mountain
nature
obstacle
outdoors
outside
patency
pedals
people
pine
ride
rider
riding
rock
slow
snow
snowy
sport
stone
stones
stuck
trail
travel
tread
trees
turn
vehicle
wheel
winter