Shǒujī yǐjīng chéng le xiàndàirén de bìbèi gōngjù.
Smartphones have become an indispensable tool for modern people.
Tips
usage
必备 is often used attributively before a noun: 必备技能 (essential skill), 必备知识 (essential knowledge), 必备品 (must-have item). Very common in product marketing and listicle titles.
