Which letter-cluster will replace the question mark (?) to complete the given series?

TMT, ZOB, FQJ, LSR, ?

Which letter-cluster will replace the question mark (?) to complete the given series?

F, E, I, G, L, I, O, ?

Which letter-cluster will replace the question mark (?) to complete the given series?

HFK, KHM, ?, QLQ, TNS

Which letter-cluster will replace the question mark (?) to complete the given series?

CABQ, CEJC, CIRO, CMZA, ?

A series is given with one term missing. Select the correct alternative from the given ones that will complete the series.
 RTM, VZX, ZFI, DLT, ?

Which letter-cluster will replace the question mark (?) to complete the given series?

ZXE ZWD ZVC ? ZTA

Which of the following letter-clusters will replace the question mark (?) in the given series to make it logically complete?
 WDV, TGS, QJP, NMM, ?

Which letter-cluster will replace the question mark (?) to complete the given series?

TQT, ZSB, FUJ, LWR, ?