Naaqs
[医][=National Ambient Air Quality Standards]国家环境空气质量标准
🗣️ 情景例句
I'll have to stand up and let the elderly lady have my seat.
我得起来把座位让给这个老婆婆。
I like dressing up in old-fashioned clothes.
我喜欢穿着老式的服装。
Two return tickets to London,please.
买两张到伦敦的往返票。