School	Characteristics of the School	Grade	Number of participants
#1	A primary school attached to a university, located in downtown, Beijing	4^th	171
#1		5^th	120
#2	An urban-rural primary school in Beijing	4^th	107
		5^th	89
		6^th	102
#3	An urban-rural primary school in Beijing	4^th	91
		5^th	53
		6^th	50
#4	A primary school in a new town of Beijing	4^th	60
		5^th	48
		6^th	41
#5	A primary school in a new town of Guangzhou	4^th	259
		5^th	259
		6^th	229
#6	A top primary school in downtown of Xi’an	4^th	162
		5^th	107
		6^th	148