英文關鍵字
adult
aquatic
beak
bill
bird
black
brown
clip
cygnets
cygnus
disappear
disappearing
dive
diving
duck
ducklings
feathers
floating
fowl
lake
movie
nature
necked
plumage
pond
reflection
resurface
sink
small
splash
submerge
swan
swans
swimming
trace
two
video
water
waterfowl
wildlife