英文關鍵字
active
aerodynamic
air
altitude
bottom
control
controlled
direction
drone
electric
engine
enjoy
fan
flies
flight
fly
fun
helicopter
high
hobby
indoors
inside
leisure
light
lightweight
machine
model
motor
nobody
opposite
piloting
plastic
play
playing
pleasure
power
propeller
radio
rc
recreation
remote
rotor
scalemodel
small
speed
toy
transmission
turning
vehicle