coin-operated rocking car, dad's father is called grandpa. Dad's father is called grandpa. This is a children's shake, which teaches children how to address their loved ones.

The song of rocking the car is Family Courtesy Address Song, which is a children's song introducing family address. This children's song teaches the baby how to address the family and friends around him politely. The lyrics are simple, which makes the children feel close and easy to understand, and can improve the baby's language learning.