示例:
Rules are made in public places to restrict(限制) people's behaviour(行为). There are some rules in the library too. Then how shall we follow them? First,we should keep in mind that the library is a place for reading and studying. So we mustn't talk loudly,run,eat or drink in the library. Second,we should keep the books clean. And we should put the books in order after we finish reading them. Last but not least, we mustn't litter in the library. We should put rubbish in the bin.
