UNIT 1 long_a
UNIT 2 long_i
UNIT 3 long_o
UNIT 4 long_u
UNIT 5 bl cl fl
UNIT 6 gl pl sl
UNIT 7 br cr dr
UNIT 8 fr gr tr
UNIT 9 sk sm sn
UNIT 10 sp st sw
UNIT 11 ch sh
UNIT 12 th wh