青酸 せいさん中毒 ちゅうどくではありませんでした
seisan chūdokudewārimasendeshita

Noun
Desu Copula

The polite, past negative form of 青酸中毒

1. Was not cyanide poisoning.; Was not due to cyanide poisoning.

Past/Perfective
Negative
Polite
Formal Register