Naaqs
[醫(yī)][=National Ambient Air Quality Standards]國(guó)家環(huán)境空氣質(zhì)量標(biāo)準(zhǔn)
??? 情景例句
It took years of hard work.
那需要多年辛苦工作。
She is hard to please.
她很難取悅。
The lady who is standing behind the counter.
站在柜臺(tái)后面的那位女士。