What does it mean for a family of three generations and four policemen?

A family of three generations and four policemen refers to a family of four people, grandparents, parents and myself, who are engaged in the police profession. It runs in the family is it runs in the family, including grandparents, parents and sons. It runs in the family's family members are the nearest relatives, lineal relatives and relatives with broken bones and tendons. Four policemen mean that the profession that four people are engaged in is the profession of police. A family of three generations and four policemen refers to a family of four people, grandparents, parents and myself, who are engaged in the police profession.