R1U1B3B3L1E1
10 points
RUBBLE is validvalid
to reduce to broken pieces [v RUBBLED, RUBBLES, RUBBLING]
to reduce into pieces [v RUBBLED, RUBBLING, RUBBLES]
to reduce to broken pieces [v RUBBLED, RUBBLES, RUBBLING]
to reduce into pieces [v RUBBLED, RUBBLING, RUBBLES]