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Schedule a Tour

    University of South Carolina （USC) is famous for its warm southern hospitality（好客）. Schedule a visit and feel it in person. Our walking tours are led by current students, called University Ambassadors, who are looking forward to telling you what it's like to live and study in USC. Our walking tours run Monday through Friday and most are around 2 hours. The university will be closed on Tuesday, July 4, 2017 in observance of the holiday. We welcome your visit year round and will be ready for you, rain or shine. Please refer to the list below to determine which tour is best for you and remember to book at least two weeks in advance.

如图所示的转化关系中，已知A是由短周期元素组成的酸式盐．D、Y、H为气体，X为无色液体，G和K均是常见的强酸．H与Na₂O₂可发生化合反应，生成的盐与Ba²⁺反应可生成不溶于稀G的白色沉淀，一个D分子中含有10个电子．试回答下列问题：

在这个世界上，只要你有真实的付出，就会发现许多门都是虚掩着的：在商界中，你付出智慧，就会发现财富的大门是虚掩着的；在感情上，你付出真诚，就会发现友谊的大门是虚掩着的；____，____,____

河南省开封市西北，有一座5A级风景区一清明上河园。有一片建筑高挂“瓦子”的标志，瓦子是北宋东京城里(  )