BBC3 年
The structure of the digestive system
The digestive system breaks down food into tiny particles ... specialised structures called villi which have a tiny hair-like structure poking into the small intestine to absorb digested food.
BBC2 年
The structure of the digestive system
The digestive system breaks down food into tiny particles ... specialised structures called villi which have a tiny hair-like structure poking into the small intestine to absorb digested food.