一口气英语怎么说

at one blast或者at a heat

在句尾+in one breath

侧重于无间断，一口气完成：in one breath/ without a break侧重于叹气：with a long sigh侧重于轻松：sigh of relief侧重于紧张：draw a deep breath所能想到的“一口气”的语境差不多就这些了，如有缺漏错误还望指正。

你必须一口气吹灭蜡烛Youmustblowoffthecandlewithoneblow.Youmustbeablowoutthecandles.Markblewoutallthecandlesonthecakejustnow.Youmustblewthecandleinonebreath.

at one go 比如：He ran to the 10th floor at one go.