致死 ちし突然 とつぜん変異 へんいじゃありませんでした
chishitotsuzenhen'ijārimasendeshita

Noun
Desu Copula

The polite, past negative form of 致死突然変異

1. Was not fatal sudden mutation.; Was not a fatal, sudden change.

Past/Perfective
Negative
Polite
Terminal Form