窒素 ちっそ酸化 さんか ぶつではありませんでした
chissosankabutsudewārimasendeshita

Noun
Desu Copula

The polite, past negative form of 窒素酸化物

1. Was not nitrogen oxide.; Was not a nitrogen oxide.

Past/Perfective
Negative
Polite
Formal Register