Li, Lei
Zhu, Jianjun
Funding for this research was provided by:
Project supported by the Major Program of the National Social Science Foundation of China (Grant No.18VZL009)
Article History
First Online: 2 April 2020
Compliance with Ethical Standards
:
: The authors declare that they have no competing interests.
: The study was in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.
: Informed consent was obtained by all individual participants and their parents/teachers included in this study.