illness是可数名词吗

illness是名词 但是不可数 1.患病(状态);身体不适[U]During his illness, John stayed indoors. 约翰在生病期间足不出户。2.(某种)疾病[C]I have never seen her since her father fell sick of a serious illness. 自从她父亲生重病后,我就再也没有见过她。