Let's not look for reasons from the outside for the time being (to investigate, where did the child go? Is there a similar training point in the local area? What are their advantages? Internally, whether the level of teachers can adapt to the continuous improvement of students' teaching and whether the teaching methods are accepted by parents and students; Whether the on-site conditions of teaching and training are perfect and whether the necessary living conditions are available; How far is the lost student's home from the training point and whether the transportation is convenient; Is there anything that makes parents dissatisfied with the fees and management? ......