The new office chairs feature a concave backrest that supports employees during long meetings.

新的辦公椅採用凹面椅背，能在長時間會議中支撐員工的背部。

Please pack the concave glass lenses separately so they are not damaged during shipping.

請將凹面玻璃鏡片分開包裝，以免在運送途中受損。

The hotel lobby has a concave ceiling that makes the space feel much larger to guests.

飯店大廳的天花板是凹面設計，讓房客覺得空間寬敞許多。