Fill in the blanks in the series by looking at the letter pattern.

CMM, EOO, GQQ, __ , KUU

The missing term in the series CMM, EOO, GQQ, __, KUU is I SS.

Here's the pattern breakdown:

• First letter: C, E, G, __, K
  The sequence increases by 2 each time (C→E→G→I→K).
• Second and third letters: M, O, Q, __, U
  The sequence increases by 2 each time (M→O→Q→S→U).

So, the missing term is ISS.

Thus, the complete series is:
CMM, EOO, GQQ, ISS, KUU.