こう性能 せいのう爆薬 ばくやくではありませんでした
kōseinō baku yakudewārimasendeshita

Noun
Desu Copula

The polite, past negative form of 高性能爆薬

1. Was not high-performance explosive.; Was not a high-performance explosive.

Past/Perfective
Negative
Polite
Formal Register