background

black

blackboard

blank

board

caucasian

chalk

chalkboard

class

classroom

college

concept

copy

education

educator

empty

finger

forefinger

gestures

gesturing

hand

hold

index

isolated

knowledge

learn

learning

left

lesson

man

people

point

pointing

school

science

showing

space

student

study

surface

teach

teacher

teaching

text

texture

university

write