What should come next in the following letter sequence?

A A B A B C A B C D A B C D E A B C D

In the following question, from the given alternative words, select the word which cannot be formed using the letters of the given word.
ERADICATE

In the following question, which one set of letters when sequentially placed at the gaps in the given letter series shall complete it?
efg _ _ eff _ ghhe _ eff _ gggh _ h

A series is given with one term missing. Select the correct alternative from the given ones that will complete the series.
DK, FN, HQ, ?

A series is given with one term missing. Select the correct alternative from the given ones that will complete the series.

L, O, Q, T, V, ?

Which one set letters when sequentially placed at the gaps in the given letter series shall complete it?

M__OMMN__M__NOMMN__M

In the following question, from the given alternative words, select the word which cannot be formed using the letters of the given word.
HANDSOME

A series is given with one term missing. Select the correct alternative from the given ones that will complete the series.
C11, V17, O23, ?