パーフルオロカーボンでしょう
pāfuruorokābondeshō

Noun
Desu Copula

Expresses probability in a polite manner ("probably…") of パーフルオロカーボン

1. Perfluorocarbon, likely.; Probably a perfluorocarbon.

Polite
Presumptive
Conjecture
Chemistry