be suddenly serious
基本解释
- 撂下脸来
英汉例句
- The pollution result that once petroleum development in Songhua river appears suddenly accident will be very serious.
松花江上石油开发中一旦出现事故其污染所造成突发事故将是十分严重的。 - WARNING: The Floormen should always be aware of the tremendous force that can be applied and that the tongs could fly off suddenly, causing serious injury or fatality.
警告： 钻工应该随时注意巨大的拉力会造成大钳突然飞出而造成严重的人员伤害或死亡。
blog.sina.com.cn - Serious thought needs to be done by those who live there, to plan for such an emergency, which could come upon them suddenly during a deluge.
居住于该地的人们需要对此进行认真严肃的考虑，为这种紧急情况未雨绸缪，因为在大洪水时，该状况会突然出现在他们面前。