学进去

The students were ___________their chemistry (化学) class. Miss Li was telling the children what water was__________. After that, She asked her students, "What's water?"___________one spoke for a few minutes. Miss Li asked again, "Why don't you answer my___________? Didn't I tell you what water is like?" Just then a boy put up his hand and said, "Miss Li, you told us that water has no colour and no smell. But___________to find such kind of water? The water___________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."