英文關鍵字
area
birth
birthrate
child
childhood
climbing
colorful
creepy
declining
empty
fertility
future
ghost
growing
growth
horror
human
hunted
infertility
intermittenly
irons
kids
lack
metal
move
natality
nature
nowadays
numbers
outdoors
outside
park
play
playground
population
populations
rate
rates
reference
scary
spooky
sterility
swing
swinging
technology