耐熱 たいねつ材料 ざいりょうではありませんでした
tainetsuzairyōdewārimasendeshita

Noun
Desu Copula

The polite, past negative form of 耐熱材料

1. Was not heat-resistant material.; Was not a heat-resistant material.

Past/Perfective
Negative
Polite
Formal Register