Practicing Success
Select the combination of letters that when sequentially placed from left to right in the gaps of the given letter series will complete the series. c _ cce _fcdc _ _ ef _ _cc _ e _ |
ecdefcde eecdeefc dececdef fcfeefcd |
dececdef |
c d c c e e f / c d c c e e f / c d c c e e f d e c e c d e f |