A double-nuclear family means that both husband and wife have their own core of the family center (the only child) before marriage, and they do not know how to act in a non-core way after marriage, so there are two cores in the family.
Which of the following options belongs to a dual-nuclear family?
Xiao Wang and Xiao Li are only children. After they set up a family, their husband sang and followed their wives and respected each other as guests