Australian hard rock band who open with the distinctive sound of bagpipes in their 1975 anthem "It's a Long Way to the Top"

Column's partner3 Go bad, as a banana3 Kind of hygiene for a dental student4 "As you ___" ("Return to the previous position")4 In ___ We Trust (U.S. motto)3 Space between teeth3 Black-and-white seal predator4 "D" in CD4