阅读理解。 The students were having their chemistry (化学) class. Miss Li was telling the children what water was like. After that, she asked her students, 'What's water?' No one spoke for a few minutes. Miss Li asked again, 'Why don't you answer my question? Didn't I tell you water is like?' Just then a boy put up his hand and said, 'Miss Li, you told us that water has no color 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.' 1. The students were having their _____ class. A. English B. Chinese C. chemistry D. moths 2. Miss Li was telling the children what _____ was like. A. water B. air C. earth D. weather 3. A boy said, 'The water in the river behind my house is always _____.' A. white B. black C. clean D. clear 4. Most of the children _____ the boy. A. agreed with B. wrote to C. heard from D. sent for 5. The water in the river has color and smell because it is getting _____. A. more and more B. less and less C. cleaner and cleaner D. dirtier and dirtier