smoke - ash - mountain
volcano
color - sun - rain
rainbow
fly - airport - travel
plane
human - number - area
population
head - rest - bed
pillow
immune system - immunity - antibodies
vaccine
small - chopsticks - white
rice
milk - sour - white
yoghurt
ocean - shell - tail
lobster
sun - earth - satellite
moon
bug - cocoon - leaves
caterpillar
farm - fluffy - baby
lamb
words - pages - spine
book
clear - healthy - glass
water
subject - school - living
Biology
wood - lead - eraser
pencil
teeth - paste - clean
toothbrush
bed - night - tired
sleep
fruit - sweet - yellow
pineapple
spice - sweet - white
sugar
door - lock - open
key
play - bounce - throw
ball
fun - play - people
game
clock - hour - minute
hand