Parents and children look at 3D printing models during a caring activity in Anning District of Lanzhou, northwest China's Gansu Province, Aug. 27, 2020. A caring activity for left-behind children in rural areas was held at a construction site of a women and children's hospital in Lanzhou on Thursday. Experts and volunteers conducted safety knowledge education to children and communicated with parents who are migrant workers here on family education and communication between parents and children. (Photos: Xinhua/Chen Bin)

Parents and children attend a parent-child activity in Anning District of Lanzhou, northwest China's Gansu Province, Aug. 27, 2020. A caring activity for left-behind children in rural areas was held at a construction site of a women and children's hospital in Lanzhou on Thursday. Experts and volunteers conducted safety knowledge education to children and communicated with parents who are migrant workers here on family education and communication between parents and children.

A volunteer introduces the construction situation during a caring activity in Anning District of Lanzhou, northwest China's Gansu Province, Aug. 27, 2020. A caring activity for left-behind children in rural areas was held at a construction site of a women and children's hospital in Lanzhou on Thursday. Experts and volunteers conducted safety knowledge education to children and communicated with parents who are migrant workers here on family education and communication between parents and children.

A child plays during a caring activity in Anning District of Lanzhou, northwest China's Gansu Province, Aug. 27, 2020. A caring activity for left-behind children in rural areas was held at a construction site of a women and children's hospital in Lanzhou on Thursday. Experts and volunteers conducted safety knowledge education to children and communicated with parents who are migrant workers here on family education and communication between parents and children.

A child tries out a VR device in Anning District of Lanzhou, northwest China's Gansu Province, Aug. 27, 2020. A caring activity for left-behind children in rural areas was held at a construction site of a women and children's hospital in Lanzhou on Thursday. Experts and volunteers conducted safety knowledge education to children and communicated with parents who are migrant workers here on family education and communication between parents and children.

A staff member of the China Construction Third Engineering Bureau Co., Ltd. introduces safety knowledge to children during a caring activity in Anning District of Lanzhou, northwest China's Gansu Province, Aug. 27, 2020. A caring activity for left-behind children in rural areas was held at a construction site of a women and children's hospital in Lanzhou on Thursday. Experts and volunteers conducted safety knowledge education to children and communicated with parents who are migrant workers here on family education and communication between parents and children.

A staff member of the China Construction Third Engineering Bureau Co., Ltd. displays 3D printing model during a caring activity in Anning District of Lanzhou, northwest China's Gansu Province, Aug. 27, 2020. A caring activity for left-behind children in rural areas was held at a construction site of a women and children's hospital in Lanzhou on Thursday. Experts and volunteers conducted safety knowledge education to children and communicated with parents who are migrant workers here on family education and communication between parents and children.