Sputum comes from your lungs and is usually thick, while saliva comes from your mouth and is thin and watery.

痰来自肺部，并且通常很粘稠；而唾液来自口腔，是稀薄和水状的。

youdao

Sputum comes from your lungs and is usually thick, while saliva comes from your mouth and is thin and watery.

痰来自肺部，并且通常很粘稠；而唾液来自口腔，是稀薄和水状的。

youdao