①是现代市场经济运行必不可少的条件

②是发挥政府在资源配置中起决定性作用的关键

③旨在形成以道德为支撑、法律为保障的社会信用制度

④要规范企业行为，引导企业以实现社会效益为根本目的

    Hi, everyone. I'm glad to show you around our city.

Now we are standing at Qingnian Square. ____ It is the white building over there. And it's on Changqing Street. Next to the bank is a bookstore. Many people go there to buy books. Go along Changqing Street.____. It is at the end of the street. Then turn left into Hengshan Road, and our school is on the right____. We sometimes walk along Hengshan Road to go to the swimming pool after class.____ Oh, there is a small river outside the city. ____ It is great fun.

从A, B, C, D四个选项中选择恰当的句子填入文中空缺处，使内容完整，正确。