Observe the following incomplete letter sequence carefully. A specific pattern governs the order and repetition of the letters. Choose the option that best fills the blanks to complete the sequence logically and symmetrically.
x y _ z _ x _ z _ z x _ z z z

Which one set of letters when sequentially placed at the gaps in the given letter series shall complete it?
g _ _ g _ _ g h _ g _ i

Select the combination of letters that when sequentially placed in the blanks of the given series, will complete the series.
REMRRE_R_EEMRRE_M_

In a given letter series, some of the letters are missing, which are given in that order as one of the alternatives below it. Choose the correct alternative.
Series:
no _ _ nom _ _ o _ o _ o _ o

Select the option that represents the letters that, when sequentially placed from left to right in the blanks below, will complete the letter series.
A _ _ F D _ S G F _ A _ _ F D A S _ _ D