They are all the examples of organ system.
When boys go through puberty their voices change and they start to grow hair on different area of their body such as their chest, face and pubic area. Also they will start to get acne
Touching a hot pan and yanking your hand away--That is nervous system.
Going through puberty is controlled by the pituitary gland.
jumping up and down is controlled by the muscular system.
Breathing harder during a jog is controlled by the respiratory system.
Getting energy to sit through class by eating cereal and a banana is controlled by digestive system and muscular system.
hope it helps
Repetition, rhyming ... that's all I can think of
