Answer:

bcde

AnswerCrossword Clue
BCDEBetween A and F
BCDE"A ... ...": kids' song beginning
BCDEA follower?
BCDEA followers
BCDEAlphabet run
BCDEA train?
BCDEThey follow A
BCDEThe A train?
BCDEA following
BCDEBetween a and f
BCDEA-F connection
BCDEAlphabetic quartet
BCDEA-F links
BCDEAlphabetic run
BCDEA following?
BCDEFour after the first?
BCDEA-F linkup
BCDEA-F filler
BCDEF preceders
BCDEA-F link
BCDEThey lead to an F
BCDEAlphabet quartet