/kloc-Xiao Ye, 0/7 years old, and her sisters came to work in a shoe factory in the city from the countryside with hope. Two years later, they strangely contracted a serious illness: dizziness and fai

/kloc-Xiao Ye, 0/7 years old, and her sisters came to work in a shoe factory in the city from the countryside with hope. Two years later, they strangely contracted a serious illness: dizziness and fainting. (1) ventilation; ②;

(2) The density of benzene is smaller than that of water, and it floats on the water surface, making the water anoxic; Physics; adsorbability

(3)

(4) acidic potassium permanganate; Decolorization of potassium permanganate solution