WHAT IS THIS?

• watermelon

• strawberry

• acne (mụn)

• chalk

• seashell

• tooth

• light bulbs

• housefly eye

• bubbles

• bacterium (vi khuẩn)

• virus

• pollen (phấn hoa)

• onion

• human skin

• paper

• sugar

• sand

• salt

• flowers

• chemical reaction (phản ứng hóa học)

• SARS-CoV-2 virus

What is this?

• honey bee's eye

• the tip of the ball-point pen

• magnet