The students were having their chemistry class. Miss Li was telling the children what water was like. After that, she asked her students, "What's water?" No one spoke for а few minutes ·Miss Li asked again, "Why don't you answer my question? Didn't I tell you what water is like?
Just then а boy put up his hand and said, Miss Li, you told us that water has no colour and no smell · But where to find such kind of water ? The water in the river behind my house is always black and it has a bad smell "Most of the children agreed With him.
"I'm sorry, children "said the teacher, Our water is getting dirtier and dirtier · That's a problem.
