@DougSalzmann @AbraarKaran @denise_dewald @LazarusLong13 School busses are easy in theory. Crack two windows and wear decent masks = near zero transmission. Schools are much harder.
@DougSalzmann@AbraarKaran@denise_dewald@LazarusLong13校车理论上很简单。打开两扇窗户，戴上像样的面罩=接近零传输。学校要困难得多。