Переведите, . a drop of blood do you know that we have between 250 and 300 million red cells in each drop of blood? as for the white cells there are only about 350 to 500 thousand of them in a drop of your blood so long as you are in good health. but suppose ' you get an infection—appendicitis, for example. almost immediately the number of white cells begins to increase until you may have as many as a million and a halt in a drop of blood. the disease germs produce certain chemicals in the body. these chemicals make the white cells divide, so that each white cell produces two new cells. the chemicals also stimulate the movement of the white cells toward the place where the germs arc causing the infection. then, when a white cell is close to a germ, it is further stimulated to change its shape. it wraps 2 the germ up. the germ is now inside the white cell, which then proceeds to digest it. so we can say that the white cells really eat up disease germs. our blood also has proteins in it. and it has a lot of little cells called platelets, which contain a special chemical. ordinarily, of course, this chemical stays inside the platelets. but, suppose, you cut your finger. the blood comes to the surface of the wound and the platelets break down. the chemical is released and it starts to affect the gelatin — like protein in the blood, building a network of fibres. soon the network is big enough to form a jelly-like stopper for the wound. we say that the blood has clotted and the wound stops bleeding.