As we know, ______ is good exercise and it is necessary for health.

 [ ]

A. walk

B. to walk

C. walking

D. walked

女性，33岁，自幼反复发作性咳嗽，伴大量脓痰，偶有咯血，近1周来高热痰多，体检：双下肺广泛湿性啰音，经抗生素治疗，体温开始下降，咳痰变清（）

A.黏液痰伴痰栓

B.脓性臭痰

C.静置后分层的浆液黏脓性痰

D.粉红色泡沫痰

E.铁锈色痰下列疾病咳痰的性状如何