And it was discovered, and WHO endorses this, that a clean cotton garment folded eight times over, can reduce bacteria up to 80 percent from water sieved through.
人们发现，并且世界卫生组织也赞成这一点， 一件棉布外衣折叠八次后 可以从渗过的水中减少百分之八十的细菌。