[解析]
We all know that Xi'an is applying for the national civilized city,what should we do ,parents and the old speak to them politely,We should help those who are in need and be friendly to the people around us(高分句型一),we'd better offer our seats to the old people in the bus,Being a polite person also needs us not to speak loudly in public,we should protect the environment,we mustn't step on the grass or pick flowers.(点明主题
Xi'an is our hometown.Let's try our best to make it a civilized city(高分句型二)(总结全篇并呼吁大家一起努力).