Unclued lights make five pairs with something in common.
 

Across

1    Fragrant nuts announced (5)
4    Neat workers secure line for pole holding basket (9, hyphened)
9    Unsuitable papal rooms exchanged (10)
11    Incitement to hold round dance (5)
15    Proud to pull tons (5)
21    I waited outside as daughter went for some clothes (8)
22    Secret group, leaderless, keeps a team away from main branch (7)
24    Buffalo product, hot, full of goodness? The opposite (4)
25    What were piped away by force out of huge quantities (4)
27    Cudgel knocks out sick Irish girl (7)
28    Arrange to fight new timetable: I lost (8)
33    Owl’s nose? (6)
34    After college,...