窒化 ちっかホウ ほうそじゃありませんでした
chikka hōsojārimasendeshita

Noun
Desu Copula

The polite, past negative form of 窒化ホウ素

1. Was not boron nitride.; Wasn't boron nitride.

Past/Perfective
Negative
Polite
Terminal Form
Chemistry