ナフテン けい炭化 たんか水素 すいそでしょう
nafutenkeitankasuisodeshō

Noun
Desu Copula

Expresses probability in a polite manner ("probably…") of ナフテン系炭化水素

1. Naphthenic hydrocarbons; Probably naphthenic hydrocarbons

Polite
Presumptive
Conjecture