Center letter: b
Outer letter: c h k l o s
Answers (40):
  schoolbook
  schoolbooks
  blob
  blobs
  bloc
  block
  blocks
  blocs
  bobs
  bock
  bocks
  boho
  boll
  bolls
  bolo
  bolos
  boob
  booboo
  booboos
  boobs
  boohoo
  boohoos
  book
  books
  boos
  bosh
  boss
  cobs
  cookbook
  cookbooks
  hobo
  hobos
  lobo
  lobos
  lobs
  lookbook
  lookbooks
  slob
  slobs
  sobs