Tongzi refers to people from all walks of life who are reincarnated as humans. Generally speaking, young people generally have troubles in their youth and are more prone to disasters than ordinary people. Whether a boy is a boy or not can be calculated through the fixed prediction method of horoscopes, or through a spiritual medium. See it. Usually a true boy needs to be replaced, otherwise things will go wrong. There is a saying that "nine out of ten people are boys". It means there are many children. Not only children are called Tongzi. If children are not changed, they are prone to serious dangers. Even in middle age, they are prone to sudden illness and death.