RAZ分级阅读 · RAZ I级
My Skin
What is my body's largest organ? It's my skin!
My skin works as part of a system to keep me alive. My skin's main job is to protect me. It protects me in many ways.
It keeps out many harmful germs and rays from the Sun.
It also helps my body when it gets too hot or too cold.
My skin has three layers. There is a thinner, outer layer and a thicker, middle layer. Then, there is a layer of mostly fat that connects my skin to my body.
