adult

beach

bottle

boy

building

bulldozer

childhood

children

city

class

color

copernicus

cute

dig

europe

hand

heavy

industry

institute

knowledge

kopernik

lab

landmark

learning

little

load

loader

machine

male

medicine

museum

object

playful

playground

playing

road

schoolboy

science

scoop

studying

summer

technology

toy

tractor

transportation

travel

visitors

watching

yellow