Warning flags at stations throughout town, he said, announce the risk level of an eruption, from green, indicating low danger, to red, meaning an eruption is imminent.

他表示，观测站的预警标识在戈马城到处都有，这些标识会显示喷发的风险等级，绿色代表低危险性，红色则代表喷发即将来临。

youdao

Adding/removing a LOW priority warning = -1/+1.

添加/移除一个LOW优先级的警告扣/得1分。

youdao

Arsenic poisoning from drinking water has become a serious human health threat throughout the Indian subcontinent and a bio-sensor may serve as a low-cost early-warning system.

由于饮用水砷中毒已成为危害整个印度次大陆的严重问题，生物传感器作为一种低成本的早期预警系统可以检测可能对人类健康构成威胁的饮用水。

youdao

You might have to stay away from low-lying areas for as long as twenty hours after the first warning.

VOA: special.2011.06.07

In hindsight the low ratios were warning flares.

FORBES: Beyond Low Price-Earnings Ratios

He opened the coop and stuck his hand in toward the fierce creature inside, eyes yellow, beak sharp as a cat's claw, trilling a warning so low it was almost a growl.

NPR: Excerpt: 'The Prince of Frogtown'

The British Medical Association has dismissed this, arguing they had been warning stocks were running low for weeks and claiming not all of the doses may have gone to GPs - pharmacists and primary care trusts also stock the vaccine.

BBC: NEWS | Health | Q&A: Flu jabs