(also to ring/sound the alarm bells)敲响警钟;发出危险预警
to warn people about a serious problem or danger
Healthcare workers have been sounding the alarm bell about the shortage of hospital beds for several years. 几年来，医护人员一直在发出医院病床短缺的危险预警。
She is ringing the alarm bells about the world's lack of action on climate change. 她正在对世界在气候变化问题上缺乏行动发出危险预警。
The steel industry is usually the first sector to sound the alarm bells over rising imports.
I wrote this book to sound the alarm bell now, while we still have time to prepare to defend our country.
It's not time to ring the alarm bells just yet, but we do need to keep an eye on the economy.
See also: alarm bell