IOWA CITY — Bunk beds, mini-fridges, microwaves and hangers. Parents filling bins with bags, stuffed with pants and sweaters. Roommates sorting mine from yours. Checking out the names on doors. The ritual restarts anew. Behold, the move-in tango. “Just throw it on the floor,” Mackenzie Hill on Tuesday told one of several helpers, who ignored her and tossed an armful of shirts onto her new bed in the Burge Residence Hall room she’ll call home during her freshman year at University of Iowa.