海水 かいすい淡水 たんすい じゃなかったです
kaisuitansuikajanakattadesu

Noun
Desu Copula

The polite, past negative form of 海水淡水化

1. Wasn't desalinating seawater.; Wasn't doing seawater desalination.

Past/Perfective
Negative
Polite
Casual Register