明暗 めいあん境界 きょうかい せんじゃありませんでした
meian kyō kaisenjārimasendeshita

Noun
Desu Copula

The polite, past negative form of 明暗境界線

1. It wasn't the boundary between light and darkness.; It wasn't the line between brightness and gloom.

Past/Perfective
Negative
Polite
Terminal Form
Astronomy