even in today's scientific age, superstition is still widespread. many tall building, For example , do not have a floor numbered thirteen , because tenants consider this number unlucky and will not rent apartment or offices on this floor. Like ancient man , some people still carry good luck charms such as rabbit's feet to protect themselves from misfortune. many people still shudder when a black cat crosses their path; other are absolutely terrified about opening an umbrella inside the house.