|
Chemical contaminant identified as 'key focus' of investigation into vaping illness 电子烟引发疾病的罪魁祸首-化学污染物 US officials are working to track down a chemical contaminant that is potentially behind a rash of lung illnesses connected to vaping. 美国官员正集中精力调查一种化学污染物，该污染物可能与电子烟引起的一系列肺部疾病相关。 | 
