What is the only possible way to complete this sequence?
CCR, CR, SV, RBT
The answer is NCS for Nicosia.
Each sequence is the sequence of consonants from the capital of a country whose name contains only one vowel:
CCR from Accra, the capital of GhAnA
CR from Cairo, the capital of Egypt
SV from Suva, the capital of FIjI
RBT from Rabat, the capital of MOrOccO
NCS from Nicosia, the capital for CyprUs
I found this one really tricky so think it merits a 3 on the rotor scale, but it will be interesting to see how you get on.