题目

When you cut your skin, you bleed(流血). If a person loses a lot of blood, he will become ill and may die. Blood is very important. People have always known that. At one time, some people even drank blood to make them strong! When doctors understand how blood goes around inside the body, they try ways of giving blood to people who need it. They take blood from the healthy people and give it to people who need it. This is called “blood transfusion”(输血). The blood goes from the arm of the healthy person into the arm of the sick person. But there are two problems. First, it does 填上合适的长度单位“厘米”或“米”。一块橡皮长4（________） 一张桌子高60（________）一棵大树高8（________） 一座桥长30 （_________）