454+351=?,295+447=?,980+741=?
790-67=?,971-677=?,1371-736=?
63+?=824,260+?=753,1277+?=1651
84*7=?,9*49=?,808*4=?
477/3=?,448/8=?,846/6=?
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?-270=809-413,120+143+442+356=?
747-293=?+305,577+551+322-1276=?
240+?+380=922,1004+588-739-640=?
203+?-563=425,1955-677-505-400=?
到处是垃圾