------What about going out for a walk after supper?

-------______. Walking after meals is good for health.

A．I couldn’t agree more.

B．I’m afraid not.

C．I believe not.

D．I don’t think so.

有关咯血和呕血的鉴别下述不正确的是（）

A.咯血不会出现黑便

B.呕血常为咖啡色

C.出血常混有痰液见于咯血

D.咯血的pH值呈碱性

E.呕血前往往有恶心