A group of children live in Nanshan, but the school is in Beishan, and it takes time and effort to go to school every day. To overcome difficulties, we must find a way. Xiao Lingzi is really smart. She builds a conveyor belt one by one to go over the mountain. Her suggestion was approved by everyone. With the collective wisdom and the help of the teacher, they finally used the windmill to create a conveyor belt from the North Mountain to the South Mountain. Amid the singing and cheers, they successfully crossed the mountain with machinery for the first time .