Long TextExercise 19 of 81

From the point of view of an immunologist, the body can be considered as a large community of cells all working together to keep the system functioning. Some cells have jobs that keep them in the same place all the time; nerve cells, for instance. Other cells, such as blood cells, are constantly on the move, carrying…

• What metaphor is used for the human body in the passage?
• Which way to become infected is not mentioned?