1. (2020·哈尔滨模拟) Wang Hua and his 49 classmates joined in this activity of helping the homeless chil­dren. According to the form below, ___________ boys in his class gave away school things.

Students	Girls	Girls	Boys	Boys
	(clothes)	(school things)	(clothes)	(school things)
Percentage (百分比) of the whole class	28%	20%	22%	?