what is blood? it is the red liquid which comes out of your finger when you cut it because of not being careful there are about 13 pints (品脱) of blood in a man＇s body. he can give a pfnt of mood at a time to a mood bank for the use a other man who may need it. a healthy body makes up the pint of blood quickly. what does our blood do for us? it takes food to all parts of our bodies and takes waste away from them.ail the parts of our bodies are made up of cells, these cells, which are very small, all need food all the time. the blood is like a stream. the cells take what they need out of the mood stream, as plants and fishes take their food out of water. the blood stream carries food and the oxygen which it has taken up in our lungs to ail the cells in the body.

　　what makes the mood go on moving round the body in a stream? the heart sends it round. the heart keeps a stream of blood going all around the body and back again to itself. eve rywhere the mood stream does two things: supplies the cells with food and oxygen and takes away waste. it is as if the mood kept the little fires in cells burning and took away the ashes.