Children with twins or multiple births are reported with different resident ID numbers, that is, they are assigned in multiple numbers and admitted according to the facts. Children with twins or multiple births use one of the resident ID numbers to register, that is, allocation number 1, and enter the park in the same park. Twins refer to the situation that viviparous animals give birth to two individuals at a time, which is called twins for short. Twins can generally be divided into identical twins and fraternal twins. In human society, the average birth rate of twins in the world is 1∶89, which belongs to one of brothers and sisters.