①有利于建设和谐文化，培育文明风尚

②是推动社会主义文化繁荣发展的根本保证

③为中国特色社会主义事业提供道德滋养

④为社会主义现代化建设提供智力支持

先化简，再求值：5（3a²b﹣ab²）﹣（ab²+3a²b﹣1），其中a= $\frac{1}{2}$ ，b=1．

    This is Mike's bedroom. It's new and nice. Today Mike's friends, Tom and Lucy are here, too. They are playing video games. Many things are on the bed. It's messy（凌乱的）. The coat is Mike's. The T-shirt and the socks are Tom's. There is a red cap. It must be Lucy's.