英文關鍵字
air
aircraft
aircraftn
animal
architecture
army
attack
aviation
bird
blue
cloud
clouds
danger
day
doctrine
exercises
farm
field
flight
fly
flying
grass
green
height
helicopter
jump
jumping
landscape
lighting
marines
military
motion
nature
old
out
parachutes
parachutist
people
pilot
plane
propeller
real
rural
silhouette
sky
skydivers
soldiers
spring
summer
sun
sunny
sunset
task
time
travel
trees
war
water
wildlife
with