Explanation:
First and fifth generations: father, grandfather, great-grandfather, great-grandfather, son.
Second, under one roof: under one roof; Live together as a family.
If all five generations of immediate family members are alive, it is called five generations living under one roof. According to the traditional ancestral system in ancient China, appellations are divided into nine generations, namely, great-grandfather, great-grandfather, grandfather, father, self, son, grandson, great-grandson and great-grandson. The five generations living under one roof can be any of the five adjacent generations.
Extended data:
Great-grandfather is the wife and grandfather in modern times, which was often used in ancient times. In short, it is grandpa's grandfather and great-grandfather's father. Great-great-grandson is the grandson of his grandson. In ancient times, he was also called Sun Yuan, and in some areas, he was also called Basun, the son of his great-grandson. The oldest woman in the world lived until her great-grandson was born.
The eighteenth generation ancestors refer to the family members of the upper and lower nine generations. The last nine generations were fathers, grandfathers, great-grandfathers, great-grandfathers, heavenly ancestors, fierce ancestors, great-grandfathers, distant ancestors and ancestors from childhood. The next nine generations are Zi, Sun, Great-Sun, Great-Sun, Sun, Sun, Sun, Sun, Sun, Sun, Sun.