空中 くうちゅう給油 きゅうゆ でしょう
kūchūkyūyukideshō

Noun
Desu Copula

Expresses probability in a polite manner ("probably…") of 空中給油機

1. Aerial refueling tanker, probably.; It's likely an aerial refueling tanker.

Polite
Presumptive
Conjecture