You may also need to refer to the info below to ensure you don't miss out any sharps or flats when adding in the extra chords to columns (i.e. chords not in your progression but you need to when completing the blanks)

Every Key:
A major = A B C# D E F# G# A
Bb major = Bb C D Eb F G A Bb
B major = B C# D# E F# G# A# B
C major = C D E F G A B C
Db major = Db Eb F Gb Ab Bb C Db
D major = D E F# G A B C# D
Eb major = Eb F G Ab Bb C D Eb
E major = E F# G# A B C# D# E
F major = F G A Bb C D E F
Gb major = Gb Ab Bb B Db Eb F Gb
G major = G A B C D E F# G
Ab major = Ab Bb C Db Eb F G Ab